It’s fairly common knowledge that the OEM Toyota temperature gauge has a large “dead spot” in the centre of it’s range. This spot is deliberately engineered to reduce the apparent fluctuations and make the car appear to run at a constant temperature unless there is a significant problem. This works fine for most, but those of us that like to know what’s going on sooner rather than later, demand a little more detail. Many people fit an aftermarket gauge somewhere in the car, I figure, if the factory gauge is already there and can be made accurate, use it.

One of the clever guys over at ih8mud figured out the circuit and how to modify it in his 80 series. He deserves full credit for the original article and all the work behind it. There is also a version for the Toyota Surf and Hilux. 

The gauge circuit in my ‘98 HZJ105R was a little different to the earlier 80 Series, so I had to re-do the calibration to suit.
I also had the opportunity to see the inside of a post ‘04 update dash, and unfortunately, it’s quite different. Someone will need to do their own testing and research on that one.

I bench tested various setups and found the following as a simple description.

     
Bench testing w/ Digital Thermometer

Heating the sender unit in vegetable oil

Mmm, wiring.

Resistors and Diode

We do not change the 15 Ohm resistor.

There are 2 components we replace, a resistor and a diode. The diode is what makes the gauge “non-linear”. Rather than explaining what they do in a wheatstone bridge, I’ll explain their effect on the gauge.

The gauge with no input actually sits in the middle of the scale. The 75 Ohm resistor we change “sets” what temperature the middle of the scale is to be. A lower value resistor sets it higher, a higher value resistor sets the scale lower. I found the following:

• 100 Ohms = 90c
• 120Ohms = 85c
• 82 Ohms = 95c

Gauge w/ no input – centres on scale.

The small glass diode gives a non-linear (dead spot) in the needle’s range. We replace this diode with a resistor to make the gauge react “normally”. The value of this resistor determines the “range” of the gauge. A lower value resistor gives large movement for small temp changes, a high value resistor gives less movement. Using no resistor with a 90C centre means the gauge hits the red at 94.5C – a little too low.

No Damping Resistor – large deflection

I found a value of 82 Ohms gives a good range with 115C touching the Red, 125C middle of the red and 65C touching the Cold. Properly mixed coolant boils at approximately 125C – 128C at 14PSI, and I’m not interested in below 65C, as the engine is not yet at operating temp.

This combination gives me the best combination of “”operating near the middle” and “enough movement to see what’s happening”. With the above detail you can adjust your own numbers if you wish.

The 100 Ohm resistor gets hotter as engine temps increase and will possibly exceed 1 watt. I recommend a 2 watt resistor. 5 Watt is very large and may not fit or be too heavy. The temp sender resistance decreases with heat, increasing current through the resistor.
The 82 Ohm resistor dissipates less than 1/4 watt, but I used a 1/2 watt to be safe.

	Original	Modified
130
120
110
100
90
80
70
60
50

You will need the following

• OEM ‘98-‘04 Landcruiser Dash
• 2 watt, 100 Ohm resistor
• 1/2 watt, 82 Ohm resistor. 

Remove the gauge pod from car and disassemble. Be careful removing it from the car – there are 4 screws and 2 bolts. The bolts are captive and hold the plug connections, but need to be unwound a lot to release the plugs.
Remove the temperature / oil pressure gauge assembly.
Remove the 75 Ohm resistor and Diode.
Replace the 75 Ohm resistor with a 100Ohm and the Diode with a 82 Ohm.

Detailed pics below (5C steps)

	Original	Modified
130
125
120
115
110
105
100
95
90
85
80
75
70
65
60
55
50

The stock Toyota cooling system can sometimes be somewhat marginal. The suspicion for this falls on every component and modification in the system.

• Radiator (Size / Efficiency)
• Thermostat (Brand / Effectiveness)
• Water Pump (Flow, Cavitation)
• Radiator Cap (Quality, Pressure, Leaks, Recovery)
• Coolant (Freezing / Boiling points, Specific heat, Anti-corrosion)
• Hoses (Restriction)
• Engine Type (Diesel / Turbo / Petrol)
• Engine Load / Modifications (Diving style, load on vehicle, Mods)
• Gearbox (Auto Cooling, Slipping)
• Airflow (Obstructions / Restrictions In / Out, Forced / Natural)
• Ambient Operating Environment (Temp, Altitude, Terrain)
• Shrouds (Closeness to Fan, Leaks, gaps between radiators)
• Fan (Size / Pitch / Airflow)
• Fan Clutch (Lockup Temp / Stages / % Slip)
• Temperature Gauge (Damping / Accuracy)
• Bullbars / Winches / Lights / Antenna’s / Plates / Screens

Ask anyone and they’ll start listing random items from the list above that they have seen before or are suspicious of. It would appear that the issue is simply that the system is marginal in certain areas, and several small changes may be enough to tip it over the limit.

The end goal of a cooling system is to transfer heat to the surrounding air. All the other components are only there to allow this transfer to occur in some improved fashion. There are plenty of air cooled motors in existence that do not have these complexities, and they too may be subject to overheating.

It would appear that Mr Toyota VERY closely engineers his vehicles, with many parts sharing multiple purposes, and many many tradeoffs being made. This is good engineering, but it means that small changes may have many unintended impacts. Despite this, it appears the Landcruiser and Hilux are intended to be frequently modified. There are many attachment points, and the OEM design has many dealer supported aftermarket options that are not from the Toyota factory.

If all the basic checks have been performed on the cooling system – no leaks, nothing obviously blocked, quick warm up, infrequent overheating except under specific circumstances, then it is a fair bet that the overall system is simply marginal. In this case, a dramatic increase in specific areas may yield a significant benefit.

In my case the overheating was limited to situations with a pre-turbo EGT in excess of 550C. This equated to High Load or High Speed driving. Despite expectations, off-road steep terrain (sand excluded) does not yield high EGT’s. Mountain Ranges, Large Trailers, Roof Racks, High Speed or Deep Sand all would yield high EGT’s and therefore problems.

I have measured many temperature points around the engine bay, and spent some time listening to the engagement and disengagement of the fan. All this yielded much confusion rather than understanding.

I replaced most components, some twice. It was during this that I had time to closely examine and understand the Toyota Viscous Fan Clutch. Possibly more than any other component, this is the key item in the cooling system. It is this that creates the airflow, not vehicle forward speed. Without airflow, the radiator is not effective. My experience was very similar  in a Toyota Surf I had owned previously. It is common knowledge that additional Silicon Fluid will often improve these units. What is not common knowledge is:

• Brand new OEM clutches appear to be under-filled
• They can be adjusted where they engage
• There are 4 separate engagement stages
• Testing cannot be done one the bench. The device requires centrifugal force to operate.

Credit goes to Frank for his guide on how to split and refill the fan clutch. I am just explaining the operation in further detail.

It must be remembered that these types of fluid couplings always have some slip. They may slip by 98% (free spin) or 5% (coupled), but there is always slip. It is difficult to test the slip in any simple manner, and impossible to bench test. Therefore a fan that appears to be engaging and disengaging successfully, may in fact be slipping at 50%, significantly reducing maximum airflow. Worse, the slip will be only happen at high RPM and maximum load.

The key points are that there are 4 operating stages, and that there is not enough fluid to couple the system adequately.

This is why so many people report success with simply adding more fluid. Adding fluid means that when the system is operating with the valve fully open, the rings are full of silicon fluid, and not partly full. The only drive is through the fluid, so insufficient fluid will reduce maximum coupling ability. There was clearly not enough fluid in the unit to fill all the rings to the depth of the final valve.

The factory engagement points are also quite high. This reduces noise and fuel consumption, but also means maximum engagement doesn’t occur until the air temp is around 95C. Engine coolant temperature will always be higher than air temperature.

This was all tested with a Digital Thermometer.

Temperature Set Points (all at 1/2 open)

Pictures of operation:

Fan Clutch
The 2 halves opened
The “drive disc” spins freely in the housing except for the silicon fluid.
The “drive disc” and the “front half” share these closely spaced rings. It is these rings, and the silicon fluid in the gaps between them that couple the system together. The inner ring is taller than the others. The oil is slowly thrown to the outside of the system by centrifugal force.
The fluid is rated at 10000 Cst – Centistokes – a measure of viscosity
The valve that controls where the fluid flows. It operates over 4 stages: 0) Closed A) Some oil to some rings B) Some oil to all rings C) Maximum oil to all of rings This is why it seems to be more than engaged / disengaged.
The temperature sensing Bi-Metal spring on the front face that controls the valve.
The reservoir behind the valve disc in the front half where the fluid is stored. When operating it is held here by centrifugal force, and pumped here by the slipping “drive disc”
The “vanes” on the edge of the drive disc in the rear half that pump the fluid forward to the outer channel for return to the reservoir. Some slip is required to allow the pumping to occur. The slots in the back of the disc pump the fluid from behind the disc to the edges, and then to the channel at the front. The rear of the disc is not used for coupling.
The wedge shaped guides and small holes in the front half that collect the fluid from the outer channel and push it back into the reservoir.
Adding Fluid
Adjust the valve set point by loosening the 2 screws and rotating the disc. The outer valve should be 1/2 open at about 45C for Australia. (US quotes 35C). Air temp will always be less than engine water temp.
Getting the fluid level right is a little difficult and involves some guesswork. The minimum amount required is enough to fill the entire outer rim past the depth of the fins in both halves, this fully couples the unit. The maximum amount is when the reservoir in the front is full and overflows through the central hole. Not so simple though, as full is controlled by centrifugal force, so when operating it fills the “outside” of the reservoir, not the bottom. Luckily there is a fair tolerance between the two. Overfull will couple the fan all the time. Mine took 1.5 tubes of fluid in addition to the factory fill to stay a few mm below the level of the valve disc.

The tests were all done on the first layer of the drum to give maximum tension. This also places additional load on the mount due to the increased height adding leverage.

Test 1 – Drag Car on Dirt (Wheels Locked)- Passed

Test 2 – Drag Car on Dirt Up Hill (Wheels Locked) – Passed

Test 3 – Drag Car on Bitumen (Wheels Locked) – Passed

Test 4 – Drag 2 Cars Uphill on Dirt (Wheels Locked) – Rope Failed

I believe the rope failed due to 3 factors

1. The Technora fibre is wearing noticeably more than the Amsteel Blue. I have read that the high temp materials are less abrasion resistant.
2. The fairlead internal radius is too sharp compared to the external radius. The radius should be 4x the diameter of the rope.
3. The fairlead sits approx 3/4 up the height of the winch, giving a fair bend to the rope as it goes over the fairlead and down the bottom of the drum. Rope rated at 13,700lb loses strength when bent. The tighter the radius, the greater the strength loss. The numbers are hard, as it depends on the diameter or the rope, and it’s construction. 12 Strand is a good construction for bending.

I am surprised a 9500lb winch can break a 13,700lb rope.

At no point did the mount appear to bend excessively, or sustain any visible damage. There was NO permanent twist.

The fairlead mount also suffered no damage, and the rope was spliced back together easily.

I was surprised at the amount of spring in the rope, you can see it coiled up under the tree where it ended up.

I wanted to keep the weight down, so decided a 9500lb was smaller and lighter than a 12,000lb. If I needed more pulling power, I would use a pulley block.

After reading the SA 4WD Winch Review, and getting a good deal, I bought a 9500lb Ironman Winch for $625 w/ 3yrs warranty. They are claimed to be waterproof and come with what I needed. I would have preferred a Premier winch due to the brake not being in the drum making it more suited to synthetic rope, but it was out of my price range. I would really have preferred a hydraulic Milemarker, but that was really really out of my price range, especially when I factored in questions around power steering pump flow rates.

After using steel cable and hating it, synthetic winch rope was a requirement. I figured 100ft (28M) of 5/16″ (8mm) rated at 13,700LB breaking strain would do. Less rope on the drum keeps the winch closer to it’s rated pulling force. I specifically bought their “Hybrid” line, where the first 25ft is a Technora based rope, and the rest is Amsteel Blue. The Technora is more temperature stable for use on winches with a brake inside the drum. I bought mine from www.cseoffroad.com, along with the alloy fairlead, rope protector and safety thimble. The alloy fairlead was a free bonus at the time. I also grabbed 100ft (28M) of 3/8″ (10mm) Amsteel Blue winch extension rated at 19,600lb breaking strain. The separate extension allows the flexibility of simply extending the pull, connecting two different points, putting a winch block in between the two etc. You need the thicker rope size if you are going to use a winch block, as it will double the pulling force – 9500×2 = 19,000lb.

The next item was a mount. Other mounts I have seen use 6mm steel plate in various arrangements. I settled for the thickest and strongest alloy channel I could get – 8.4mm x 6.8mm tempered alloy. It doesn’t have a rated “strength” in this configuration, especially after I chopped it up to get the winch to fit. I can say that in a pull to stall test, the rope snapped before the winch stalled, and the mount, while having a slight twist, suffered no permanent deformation. The winch is in an ideal position, directly between the chassis rails, very low, and as far back as possible. The mount acts to protect the radiator from sticks etc.

The fairlead I mounted into the bullbar with 20x heavy gauge rivets. Whilst I am not that confident as to their strength, in shear the steel pins combined with the tight fit should be very strong. At a 45deg pull they will be in both tension and shear, a less desirable situation. The alloy bar mounts are particularly weak in a sideways direction, so I think I’ll be avoiding heavy angled pulls. The fairlead needed to have it’s inside edge rounded a lot, as the winch sits quite low in relation to the bar.

Finally it was just a matter of the control box hidden inside the bar, the wiring and lockout switches. I recommend the lockout switches be waterproofed underneath with silicon, and rubber caps fitted (I used rubber “feet”). Water pulls inside them and the copper contacts stop working.The winch is wired with a switch to each AGM battery, letting me use either one, or both.

By dropping the steel cable and roller fairlead, using an alloy mount, not using a 12,000lb winch and keeping the alloy bar I have kept nearly 75KG off the front of the car. Just as importantly the weight is as low and far back as possible, something most winch bars don’t do. Whilst I accept it’s not as strong as a steel winch bar, it has passed every test I can throw at it so far.

Finally – it’s a whole lot cheaper than driving into ARB, and with Mickey T MTZ’s, twin Air Lockers and some lift, hopefully I won’t need to winch too often (yeah right).

The heaviest aluminium alloy channel I could find. It is also tempered (or so the guy said). 8.4mm base, 6.8mm walls.
Trimmed to fit winch and chassis rails with lower bull-bar mounts. I should have rounded the corners more to stop fatigue.
Winch fits nice and snug.
Alloy hawse fairlead mounted in the factory bar. Yeah I know, I know. If it snaps the rivets then I’ll do something sttronger. The alloy is 6mm checker-plate. The bar is not that strong, nor are the bar mounts.
Terminating the high temp Technora fibre.
Had to grind the allen key to fit the link on the rope.
All spooled up. Rope protector is the black bit. I have a strong plastic / rubber  flap that covers this gap keeping grass and mud out.
Pic when fitted. Yes, I suspect it may snag something one day.
The lockout switches with waterproof covers. They don’t like water in them, and then don’t work.
Internals of the waterproof control box. It’s zip-tied inside the bullbar.

They are a scam, it’s so well documented I can’t even be bothered linking the hundreds of articles.

http://www.google.com/search?q=firepower+dans+data&rls=com.microsoft:*&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1

Scammers, Charlatans, Scumbags, Liars, Theives, Con Artists, Rip Off Merchants, Fools and Money.

What next – Hyclone ads? I’ve got some magic fairy dust I would like to sell you…..

Here is the testing to blow some theories away, you’ll find out which ones.

Handheld Digital Manometer
http://autospeed.com/cms/A_2905/article.html

Undertrays, Spoilers & Bonnet Vents, Part 1
http://autospeed.com/cms/article.html?&A=2159

Eliminating Negative Boost – Part 1
http://www.autospeed.co.nz/A_0629/page1.html

Eliminating Negative Boost – Part 2
http://www.autospeed.co.nz/A_0637/page1.html

Eliminating Negative Boost – Part 3
http://www.autospeed.co.nz/cms/article.html?&A=0646

Eliminating Negative Boost – Part 4
http://www.autospeed.co.nz/A_0652/page1.html

Eliminating Negative Boost – Part 5
http://www.autospeed.co.nz/A_0663/page1.html

Siting Cold Air Intakes
http://f2.autospeed.com/cms/A_1023/article.html?popularArticle

We Have a Record!
http://www.autospeed.com.au/cms/article.html?&A=109217

Negative Boost Revisited, Part 1
http://www.autospeed.com/A_107824/cms/article.html

Negative Boost Revisited, Part 2
http://autospeed.com/cms/A_107825/article.html

Negative Boost Revisited, Part 3
http://203.57.155.8/cms/A_107826/article.html

Ballistic Bellmouths
http://autospeed.com/cms/A_1266/article.html

A range of tech tips
http://blog.autospeed.com/2003/11/02/a-range-of-tech-tips/

Box Breaths – airbox testing
http://www.autospeed.com.au/A_0073/cms/article.html

http://www.neuralfibre.com/paulfiles/Cruiser_Oils.xls

Oil Filter Pics Here 

Technical info can be gleaned from links below or Google.

This analysis is not perfect of definitive. My motor is not factory and fuel system hasn’t been touched possibly every (250,000km). I have changed multiple variables each time (oil, filter, driving style etc)

What I read in this analysis is

1. I need to try 10,000KM filter changes, 5000 seems to be nowhere near capacity
2. Normal oil fine at 15,000km, could go longer. 5000 is a total waste of time and money.
3. Soot is the problem and it’s below 1micron. Very small.
4. An additional filter *may* help, but would need analysis to prove if it’s effective.
5. Although the factory Toyota filter appears to be far better constructed, it doesn’t perform any differently when changed at 5000KM, possibly worse from some of these numbers. I suspect if has far great capacity.
6. Anyone that talks oil without analysis prob has no idea

I’ll do some more testing, but it’ll take a while. I have a small diesel car for short trips now.

I am using sample kits from Castrol Labcheck at about $40 ea from Qld Diesel Spares. At $100 an oil change if I go from 5000 to 10,000 changes it pays for itself. Plus it’s interesting.

http://www.wearcheck.com/literature/techdoc/WZA026.pdf

I have been doing a program of Laboratory Oil Analysis with Castrol in conjunction with this to obtain some definitive information. None of these filters have run longer than 5000KM.

All the filters are Dual Element types. They contain two filter elements. The first is a full flow element where all the oil from the pump to the engine MUST pass through it. This will catch anything that would cause immediate damage to the engine. There is also a secondary filter stage. The secondary filter is much finer that the primary filter and only scrubs a percentage of the oil each time. Over time this effectively scrubs all the oil to a very fine level. The secondary filter is often called a bypass filter, as in many systems the oil that goes through the secondary stage bypasses the engine and goes straight back to the sump. This is not the case with any of these where the oil from both filters continues on to the engine.

These filters also contain a drainback valve and a bypass valve. The drainback valve is designed to keep the filter full and reduce the time it takes for the engine to acheive oil pressure. The bypass valve is designed so that if the filter blocks to the point where it cannot flow enough oil for the engine, it will open and allow dirty oil to circulate, something that is far better than insufficient oil flow and pressure.

It is difficult to determine when a filter is "full", and I haven’t attempted to here. This fitler design makes it more difficult, as one element may be blocked, and the other still working correctly. There are tests you could devise, or through oil analysis. I have done neither at this point in time. I would however assume Toyota put a reasonable amount of time into determining the capacity of the filter vs the service intervals.

I have heard discussion of using a Z9 type single element filter on these engines. This would be a very bad idea. The Z9 single element has no secondary stage and would not scrub the oil, so over time the oil would become more and more contaminated, significantly reducing it’s lifespan, and the wear on the engine.

I have considered using an external bypass filter element to supplement these, however am reluctant to do so until:
a) I have more oil analysis data to show the benefit
b) I have information that shows they filter to a finer level, at the moment they simply appear to have a larger capacity
c) I have some method for determining if they are blocked or approaching capacity.

None of the filters below showed any obvious signs of clogging, material build up etc. Based on no other evidence than visual, I would say these filters are nowhere near capacity at 5000KM.

The genuine Toyota filter appeared to have better quality parts throughout.

Ryco

Ryco

Ryco

Nippon Max

Nippon Max

 
Nippon Max

 
Toyota Genuine

Toyota Genuine
Much much more material in the secondary stage.

 
Toyota Genuine
Appears to have much more complex pleats and larger surface area.

Actually the catch tray in the surf was better, as it had a hole and hose leading to near the sump plug, so whatever leaked, ended up in the bucket too. This one you have to clean out manually – I use a rag. Oh well, can’t have everything I guess.

• Toyota Part Numbers are:
  Receiver, Oil 15674-17010
  Bolt, FR Oil Pump Cvr – 91511-J0820

A mate bought a brand new set of “TBC Corproation” Korean 235/85/16 muds the other day for $500 for 5. Sundown was their first trip out. The roads were bad, the Discovery fully locked.

In comparison another Defender without lockers did the same roads with some assistance. The Defender had a brand new set of Maxxis on it. My Cruiser had Mickey T MTZ’ s not pictured, here. Same roads, also minimal to no significant damage.

Tyre pressures on the Korean tyres were 22PSI initally, then dropped to 17PSI. All work was low range, generally 1st or second. There was wheelspin, but in the cheap tyres it was minimised as far as possible. The Maxxis copped more of a flogging due to not having lockers fitted to the car. Yes the rocks were hard and sharp, but the other tyres coped.

Here are the pics for comparison.

Sidewall Staked
Sidewall Torn
Shredded
More Shredded
Yes, that is steel belt you can see
Well branded
Size
Model
Load rating – Treadwear – yeah right.
Maxxis in comparison, these actually had a harder time as Defender was unlocked.
Maxxis
Bighorns – not bad at all.

The AGM construction has approximately 50% more lead in it than a normal flooded cell, and the electrolyte is not free to move around as easily as it charges. The cells are tightly packed with an adsorbent wadding leaving no room for movement.

If you overcharge an AGM or overheat it, it will bulge the top and sides. If the bulging becomes bad enough, the battery will fail. Optima tries to stop this problem by winding their plates in a spiral, a stronger construction. Odyssey tries to stop it by placing a metal jacket around the battery.

Finally, a batteries life is defined not only by how heavily it’s used, but also by what temperature it’s used at.

So when I fitted AGM’s to my cruiser, I knew heat may be an issue.

The 80 Series cruisers came with a battery heat shield, as do Falcon’s and many other vehicles. Heat reduces a battery lifespan significantly, from 10 years to 2 or less.

I found the majority of the heat was from the radiator fan blowing onto the batteries. Due to the placement of the engine, much of the hot air goes straight to the batteries. I measured battery temps of over 65c.

Now with the heatshields they don’t get over 40c, even after several hours of driving. Fast or slow doesn’t seem to matter too much.

I had two of the aluminium ones folded up and I trimmed them to size with a nibbler. I only had time to fit one before my last trip and quickly made up a temporary shield from a windshield sun reflector for the other. Both work equally well and the windshield cover is less likely to damage other parts of the car. Despite having foil in it foil, it doesn’t conduct, I have tried that in several ways, including puncturing it. 

I know people talk about radiant heat from turbo’s and exhausts being a problem. I found the 90-100 deg c air from the radiator to be far more of a problem than the radiant heat from the turbo. How do I know? Radiant would only heat the side that faces the turbo. I found the battery to be evenly hot all over – hot air.

Airflow from front of car to behind headlight to cool batteries. Previously hot air would come back through through this hole from the radiator. Poor design.
1.5mm Aluminium sheet folded and edged with rubber seal.
Blocks airflow from fan onto battery.
Battery sits on some “windscreen sunshield” as a “floor” for the box.
Plastic hose to protect sharp edges.
Cheaper rushed version before trip. Seems to work just as well.
100Mile/Hr tape and $2 sunshield.
Wrapped all around the back, top, sides and underneath.
Airflow gaps at the front to allow cool air in.
Engine close to radiator forces air to go sideways onto batteries. Fan has a large centrifugal component, so a lot of very hot air exits sideways.

Front AC panel with slot for filters

 
Barrier approx 1/3-1/2 way in

 
Another angle

 
Depth view of A/C unit – it goes a LONG way back

Another depth view

How far I can insert the filter

The one I bought is worth the money as scrap steel however – weighing in at 20KG, it weighs more than my entire drawer system. I’ll be “modifying” this to reduce weight significantly when I can afford a plasma cutter.

It’s a fridge slide. The fridge slides in and out. It kind of stays out, depending if the locking mechanism lines up that time or not. The straps it came with were a joke.
Looks like slides from a computer server or filing cabinet. Surprisingly they don’t rattle. The locking mechanism does however rattle a little, as sympathy with the travel stop which squeaks.
Very solid construction. The amount of plate steel used here is amazing. Unfortunately it wasn’t enough to stop the carpet bowing it up in the middle and rubbing on the sliding tray. You can see the rub mark where it has damaged the paint and scored the steel. The clearance here was inadequate to start with.
You can see I have screwed it down. It comes with 4 small screw holes, 2 of which are covered by the tray. Total disassembly is required to screw it down firmly.
The tray rubs underneath as well.
The offending locking mechanism that needs a grinder taken to it.

Well it’s difficult to install, requires modification from new, squeaks, rattles slightly, slides poorly, jams open, doesn’t lock open, and weighs far far too much.

BUT it is pretty solid, and could be modified to be better.

Score: 2/5
I’ll get a lightweight one. Or one of these drop ones for the missus although $449 is a bit more expensive and I haven’t seen a weight.

1. They are difficult to tighten as the lop just goes round and round as you try and tighten it.
2. They make it very difficult to remove the fridge as each strap has to be unthreaded back through it’s buckle. A tedious job for the rear ones.

Loop straps on a fridge are a silly idea.

Just Straps to the rescue. These came from BCF, even though I hate the place. Super Cheap Auto of the camping world. They are 25mm webbing rated at 150KG each. A big accident might break them loose, but I think the fridge or slide mounts will fail first.
They are in two pieces with a strong steel hook and loop connecting them. One part stays with the fridge, the other with the slide or tie-down points. The fridge end has a loop to feed through itself. The base end has a length adjustable steel buckle.
The loop that connects is together is a gripping “tiedown” tensioner, allowing a 2:1 mechanical advantage. Great for getting it down nice and tight.
All tied in, it won’t move no matter what happens.

Highly recommended. 5/5
They are quick, simple, easy and strong.

Last month saw me in Tassie for a holiday and gagging to try some of the more famous Tassie tracks. After the first decent circuit done and heading up a dirt road I hear and feel a noise – clunk clunk clunk about once per wheel revolution. I had heard a very faint noise 2 weeks before, but it was consistently only on deceleration and I had put it down to the new tyres.

A few tests quickly showed it was the diff and not a CV. 10KM back to Zeehan at 10km/hr and I disconnected the front tailshaft and knocked off the two front hub drive caps. This isolated the front diff, but did leave the front wheel bearings exposed.

Several thousand KM later back to Brisbane and a heap of tracks missed, and the diff was pulled down.

The pictures below is what was found.

The diff housing was not cleaned out after the last failure. The company that did the work was BOAB 4×4 at Lawnton run by the owner Darryl Flenady. $5000 for 2 air lockers, CV’s, bearings and seals was obviously not that well spent. I should have been more suspicious after the rear air locker failed.

The business is now in new hands – Wayne is the new owner. Wayne wouldn’t wear responsibility. The charge was $305 to remove and refit the diff and clean if properly.

The diff itself was sent off to Duncan at Top Cog in Caloundra who does the work for Boab. Duncan only charged for parts and also stripped and setup the locker with less lash. The car drives much more nicely now, it used to clunk on / off throttle. Parts cost there was $1000. Duncan indicated that the Ring and Pinion could possibly be re-used, but would most likely be noisy. Fine for a part time 4wd, but problematic in an AWD car. I agreed with that.

I say a big Thank You to Duncan at Top Cog, he has done and excellent job and none of this was his fault.

BOAB obviously was shockingly negligent last time, and although the new owner Wayne is trying, and I understand his position, I don’t believe he has worn the responsibility that comes with buying an existing business. I know I’ll be taking my money elsewhere.

The cost to me was $1305 in repairs, plus a holiday that got very mangled due to having a broken car. At $1200 return, Tassie isn’t a cheap place to go back to.

I decided on Autometer as they are know to be very high quality and if bought from the US, well priced. VDO is another well respected brand, but is getting hard to source.

I ended up buying from AtlanticSpeed as the EGT gauge (the most expensive) was US$148 vs $351 in Australia. eGauges also has a good reputation, but couldn’t supply the metric gauges I wanted at the time. Thermoguard is an Australian company that does a very good digital EGT gauge for AU$265, however I didn’t have a suitable place to mount this type and preferred the analogue style of readout.

I settled on a Diesel EGT Gauge – 3344-M as the most appropriate. It is metric, 270 deg sweep for good resolution (90 deg sweep makes it hard to pick small changes) and has a suitable range for a diesel engine, 0 – 900 C. There are many EGT gauges designed for petrol engines that go to 1200 C, however in a diesel this “wasted” and again reduces resolution. I wanted to be able to pick small changes.

There are no Autometer boost gauges that go from 0 – 15 PSI. There are plenty that do vacuum as well, however diesels generally do not generate vacuum. There were plenty that went to 30PSI, however as I am only running low – medium boost, this would again have reduced resolution. I ended up using a Fuel Pressure Gauge – 3311 for US$40.

Postage for these plus another set for a mate was US$44, keeping the cost well below what I could get similar from within Australia.

The 2 gauge pod came from eBay to suit 2 1/16″ (52.4mm) gauges.

Fitting is as below

EGT thermocouple drilled and tapped into the side of the exhaust manifold before the turbo. This is the best position to detect EGT. Hole is imperial drill size 0.332 with a 1/8″ NPT tap run through it. Any fine shavings won’t bother an exhaust turbine wheel at all as it is designed to deal with flakes of carbon. The manifold drills and taps easily. The heat shield bolts were seized so I gave up and drilled a hole in it. When tapping – use some lubricant with the tap. Be firm and keep it very square, it’s not that thick so cross threading is easy and would be bad. Use a proper tap handle and not a shifter, you won’t keep a shifter square.
A trip to a fittings and hose shop made up an adapter for the factory port in the crossover pipe and supplied the hose / adapters needed for the boost gauge. There are no ports in the manifold itself.
The wire and hose was run to allow for movement and flex
Spare length for the thermocouple should not be trimmed to maintain factory calibration. Spare length for the boost gauge helps to damp any vibration and pulsing giving a smoother reading.
I had to silver solder up an adapter for the fuel pressure gauge. It uses a flare fitting and I wanted to connect to nylon hose. Further, the pod had very tight constraints for size, so getting the length and angle just right was just right. This is probably the most difficult part.
Test fitting the two gauges in the pod. The black plastic pod received three coats of Grey Vinyl Paint to match the car interior. This paint won’t damage the plastic.
Mounted on the A pillar there is very little obstruction to vision. The distance is good enough to be clearly visible. I placed the EGT gauge further away as this makes it easier to see. The human eye can change direction quickly but is very slow to change focus. The further away your gauges are the easier it is to glance at them.

So far the 1HZ Cruiser is running 9.5PSI Boost and the following EGT’s

The fuel gauge does seem a little notchy in it’s role as a boost gauge, but works well enough and is quite precise. The EGT gauge is sensitive to electrical noise and low voltage. Make sure it gets a good feed or the needle will jump around.

So I copied my old man.

A timber shelf with plastic boxes under it, carpeted. Have boxes for day to day, and another set on the shelf in the shed for camping. It’s quick and easy to pack / unpack / change over, practical for camping as you can leave the boxes at the campsite. And cheap.

Plenty of space in the cruiser, not very useable.
A quick twist to the top mounting straps for the Milford cargo barrier moved them up, and the top of the barrier forward 15mm. Every bit helps. The mount points the instructions give you for the cargo barrier put it back 1.5″ from the seat, losing heaps of rear space.
I swapped the short straps for the long ones, re-drilled them and trimmed to length. This pic shows the short strap beside the long one. The hole in the floor is just visible.This gained 1.5″ of space at the bottom of the barrier and pushed it within 5mm of the back seat. The long straps are normally used if you mount the barrier in the “forward” 2 seat position.
A trip to Bunnings found the boxes I needed. The smaller ones on the rear of the sides are due to me needing to maintain access to the child seat mounts. It’s a combination that works well. The steel bar was to give me a level to measure to that would clear everything.
15mm structural ply for the sides. I tried 15mm for the top, but it was not strong enough to bear my weight. The top is “about” 1100 x 1100, but measure your car to be exact.I ended up using 21mm ply for the top. Tip for beginners (and me), make sure the top & bottom grain of the ply runs side to side. It is much stronger this way. I can now stand on it and it doesn’t bend.
The sides were profiled to clear the plastic trim near the wheel arches. I wanted it as wide as possible.
I used 45mm x 3mm aluminium angle in the corners to strengthen them. It’s light, cheap and strong. Angle is screwed and glued.
All joints are drilled, glued and screwed. I used the new Polyurethane wood glue, it’s much stronger than PVA and bonds to more things. All screws are 10 Gauge. They need to be drilled as you are going into the end grain of the ply.
Rear tie downs are 6mm stainless turnbuckles from Bias Boating and the U bolt from a galvanized wire rope clamp. This gives a very low profile loop. Grind the sharp points off the turnbuckle hooks, they really hurt. The floor is the factory tie down point.
Holes drilled for the kids seatbelts.The front is tied down with cam buckle straps to the front factory tie down points. Cam buckle straps are lower profile than ratchet straps. Zip tie the bottom hooks to the barrier to keep them from coming off. This gives a simple and very strong tie down. You can’t tie down to the barrier as it’s not well secured up/down. It is only strong back / forward. If you do these up first, then the turnbuckle tensions them as you do up the rear.
I used 2m x 1.5m of Marine Grey carpet and 1L of contact adhesive again from Bias. Tip: Read the instructions on the can of adhesive, it works much better that way.I deliberately didn’t put side “wings” on mine despite initial plans to do so. After trying it I found a plastic Jerry can of water fits perfectly on each side. I’m very happy with the result and storage from the boxes. Overall weight is under 15KG inc boxes. (haven’t measured it exactly). Much lighter than the cargo barrier.

The next step is a fridge slide from 4WDSystems for my Waeco CF50 and I’ll have something that is more effective than a $2500 set of drawers for $500.

I recently fitted a set of Airlift 1000 Series helper airbags to my ‘98 HZJ105 Toyota Landcruiser. They were much cheaper ($200 vs $1000+) than a pure rear airbag solution, and easy to fit. At 5psi they have little effect, but with up to 40psi they can handle 2200kg additional load on the rear as per the spreadsheet I worked out earlier. I doubt my shocks would handle that sort of load effectively.

I bought the kit from www.truckspring.com as they worked out to Au$200 delivered to my door vs Au$350+ to buy them locally. I know, support the local guy, but not at that markup. The locally supplied Polyair bags are just a rebadged Airlift kit from what I have seen and comments on various discussion boards reflect this.

The part number for a 2″ Lifted 100 Series Landcruiser is 61730
The part number for a stock GU Nissan Patrol is 61724

Installation in the cruiser was easy:

Kit is fairly comprehensive. The only problem was the hose is not long enough to run two hoses to the front of the car, and it’s a hard to match hose (but not impossible). I wanted my valves under the bonnet near the compressor, but such was not to be.

I dropped the wheels off and undid the bottom shock mounts: I bit of persuasion the got the springs out, it is easier with a second person to push down on the axle whilst the other pulls the springs. Then insert airbag and spacer.

Back in place. Run the lines with some slack up the top as the bag / spacer may move inside the spring and you wouldn’t want to pull the lines out of the nipple. At full droop a gap is normal

I ran my airlines into the T piece supplied and onto a common valve on the bumper. I figure at these low pressures and volumes, doubling the volume will help in getting a consistent pressure. Most gauges aren’t accurate down to 5PSI and the smaller the volume, the harder it is to adjust. I don’t have huge loads on one side only to need the separate side to side adjustment.  The airlines are too small to work as the Landrover system does offroad, allowing air from side to side. It would happen, but too slowly to be useful in improving articulation.

So far they are working well. Fully laden I used to bottom out my rear springs on contours etc, now it’s not a problem, I just set them to 20psi. Most (90%) of the time they are only at the minimum 5psi giving a pleasant ride.

A friend did blow some recently on dirt roads, but they were old. I know they have a finite life, which I heard once as “about the same as your tyres”. I’ll see how they go, but I imagine dirt roads are hard on them for abrasion against the spring.

I had a constant damp mist of oil near my fuel filters on my ‘98 HZJ105 w/ 1HZ engine. Looked like diesel, spread and picked up dirt like diesel, was all around the diesel filter.

It wasn’t diesel.

A lot more looking showed it to be P/S fluid blow into that spot, and several others. The hose wasn’t leaking, despite the oil on the hose that made it look that way.

More looking finally showed the leak was the flange between the cap and body of the reservoir. There were no “tracks” of oil on the body, and it wasn’t wet with oil, just damp, the fan seemed to blow most of it clear. A replacement was $125 at the wreckers, and he had 2 on the wall out the front – happens all the time he said, he sells heaps.

Being lazy and cheap I didn’t want to cough that much. A set of vice grips run around the cap tightly to re-crimp it and presto, no more leak, and one cheap fix.

Difflocks aren’t much help here.

If you are running PolyAirs or similar helper airbags in your vehicle, it’s probably a reasonable idea to know what effect the pressure you are running has compared to the normal spring.

Attached is a spreadsheet that should help you work it out.

For some reason spring loads are commonly still in lb/inch, hence the combination of imperial and metric.

My Landcruiser springs (aftermarket Kings) are approx 250lb/inch. This means for every inch compression, it means another 250lb * 0.45 (112Kg) has been added to each spring.

With full travel of 240mm (10 inches) and a normal lightly loaded ride height of 4 inches compressed = about 1000lb per spring (2000lb total) in the rear of the car. Every extra inch of compression will take an additional 112KG

Polyairs’ rate depends on several factors. The base area of the bag X pressure = the current load. Where it gets interesting is as you compress an airbag it’s rate increases exponentially. The attached spreadsheet shows this effect compared to a normal spring. What is interesting is that the polyairs in the Landcruiser only compress by some 40% of their total length. This reduces the non-linearity significantly. In fact they increase in effective load bearing capacity at a slower rate than the factory spring. This is an unusual outcome for a normally exponential device. If your car has large locators inside the springs, or compresses them near to binding, then the behavior would be significantly different.

Applying the same formula to sleeve type airbags as used on trucks and Discovery III or Range Rovers is a little more difficult, as their internal volume also consists of some spare space down the sides of the bag. This tends to reduce the effect of the rising rate somewhat. Further the piston in the sleeve type bags is often conical instead of cylindrical. This again changes the rate based on height.

It is interesting to note that the factory Range Rover airbags make the piston smaller near the base, presumably to offset the rising rate effect and be more linear. Many aftermarket bags Rover are larger at the base, making the rising rate effect more pronounced.

Flat bag type bags on the other hand would be highly exponential in their behavior.

If you play with the spreadsheet somewhat it quickly becomes evident that airbags are quite a complex suspension mechanism, and one that holds significant potential.

Twin tube shock absorbers don’t work on their side or upside down. The gas in them mixes with the oil and turns it into a foamy mess. This sends the damping rates all over the place, making it unpredictably worse than useless.

Monotube dampers are fine on their side, but not many people run monotube steering dampers. My steering damper didn’t look like a monotube.

Both of these need gas in them to allow for the space the rod takes up as the compress. Some shocks run the gas under pressure for better high temperature performance. Steering dampers do not, it would make them push the steering to one side.

Motorcycle steering dampers run the shaft out the other end, meaning the internal volume stays constant, and you don’t need a gas space. A gas space in these makes them behave very strangely, doesn’t it Brett….

I turned to a mate – Jamie – at GSA Wholesale Suspension for an answer to this one. I find they know more about shocks than anyone else I have ever found.

 It turns out steering dampers generally are a twin tube design, but the air is kept in a plastic bag or bladder. This separates it from the oil and prevents mixing. Now, even though it’s on its side, it can’t go and interfere with the valve rates.

Nifty eh….

http://www.landyspares.co.za/landyspares/files/snatch_straps.htm

My preference is not to use shackles with snatch straps unless it can’t be avoided. They will nearly always be stronger than the vehicle mount points. This means if the vehicle mount fails (likely from the debates circulating) before the strap at 8000KG, you’ll have 3kg of shackle headed toward you at high speed. You just supplied the projectile needed and you know it’s aimed straight at your vehicle.

A rated vehicle hook (not loop) circumvents this problem in a number of ways. If it fails in the hook itself there is little to become a missile, and it likely won’t stay with the strap. If the mounts or chassis fails there is a fair chance as it tears off, the strap will simply pull free of the hook. 

 In the situations where you have to use a shackle with vehicle loops there is a simple solution would provide a great deal of safety. Use a second strap – preferably a rated tree trunk protector – and connect it with shackles to two separate mount points on the car. Feed the tree trunk protector through the eye of the snatch strap. Now you have the situation where:
a) Each mount is only subject to approx 60% of the load (depending on the angles)
b) The tree protector is only subject to 60% of the load
c) If a mount fails the unraveling of the protector as it passes through the eye will significantly dampen the recoil of the snatch strap
d) If the mount fails the shackle and mount is still attached to the vehicle via the other side of the short strap – no projectile risk.

I don’t mean this as an excuse to fitting rated mounts, or as a reason to use the factory tie down points. BUT. We all know it happens and may be guilty here and there of doing the same. At least this way the result won’t be catastrophic and the only additional hardware is a second strap of some type.

It’s definitely a lot simpler than some of the techniques I have seen suggested with a rope at each end, and more reliable than a damper thrown over the strap.

This model (as opposed to the IFS models) didn’t get a bash plate or and form of protection in front of the radiator. If you look under there you’ll see that it is easy for any stick coming up to jam into the Air Conditioning condenser, and possibly into the radiator as well. If you have seen the 4WD Monthly video of Tasmania and the Prado with a smashed bottom radiator tank you’ll know exactly what I mean.

They also have a tendency to suck up every bit of seed and fluff through this gap and block the bottom of the radiator. As there is generally no foam seal between the cores, it gets into places that are a bugger to clean out.

I bought 2 strips of 40mm high density open cell foam from Clark Rubber for about $5 and jammed it in there to fill this gap. This is what the normal factory fitment is and I see the latest year HZJ105 has this foam installed. This will improve airflow through the airconditioner core, reduce recirculating airflow, and prevent seeds and bugs getting between the cores where they can’t be cleaned.

I then bought a sheet of 3mm checkerplate aluminium measuring 610mm x 470mm for $30. 2mm would have been adequate, as it’s only to deflect sticks, not to drop the car onto.

You can use the factory bashplate and steering damper bolts to secure the rear. The holes are all 8mm and are at 100mm, 180mm, 303mm, 474mm.

Once the rear is bolted up it is easy for force a bend in it with a bit of timber and the jack. I didn’t want to have to deal with loose nuts, so used tek screws to secure the front. Captive nuts are difficult with allow unless you have access to rivnuts.

This now keeps all manner of gunk out of the radiator. It should help prevent surges of water coming in on water crossings, and protect it from errant sticks coming up at it.

Cooling may be an issue, but I just towed 3500kg of trailer for 200km and had no worries on the highway. It got hot on the range, but it always has done so. I wouldn’t expect low speed cooling to be affected as that is primarily draw through from the fan. High speed is a more likely problem, and has been fine. The IFS cruisers have a slotted plate instead of a solid one, and it would be possible to slot this plate if it is a problem. It does block some airflow to the power steering loop, but again, I would expect this to get enough air from the surrounding airflow, and the metal is it bolted to.

Cheap easy protection.

Here’s the catch. To get 240V down to 12V means a battery charger. Most battery chargers only put out 4 – 8 Amps depending on the model. Expensive versions put out 10 – 16A but will cost $150-$400. Assuming the average person uses approx 40A/H per day, that’s going to take 4 – 8 hours to be replaced.

Some generators have a 12V output. It’s rated at 4 – 6 Amps. You are still looking at 4 – 8 hours runtime.

Now lets look at a car alternator. They produce 12V directly at 40A minimum in an old car. My Cruiser is 120A from factory. Most are over 80A. It’ll recharge 24Hr discharge in half an hour (if your battery can accept that much that fast).

All your stuff runs on 12V and what doesn’t can run on an inverter for the time needed. Switch mode power supplies (Laptops, Phones, Camcorders etc) are happy running off a cheap $40 inverter. They do NOT need sine wave inverters to be happy, as they convert straight back to DC anyway. Sine wave inverters are good for things with coils in them – motors and transformers.

What we need is a  high output 12V generator based on a car alternator. Currently the only one avaialable is from Christie Engineering. Nice toy, but expensive, and a little loud, not like the quiet Honda’s. A tiny diesel version would be nice too, run it off the car fuel tank. Any chinese importers want to step up to the plate, I reckon you would have an excellent market.

I have made one in the past, but it was bulkier than the Christie unit, belt driven, and needed more HP due to the RPM requirements. ie. It’s not quite simple, but it’s definately do-able.

This mainly relates to the Lokka and Lock-Rite lockers. Detroit has a similar process, however I have never pulled one apart and I believe there are some differences.

First, Mechanical lockers are NEVER locked. Any document that says they are locked is either over simplifying, or doesn’t have a clue.

They have ONE SIMPLE RULE:
One wheel will be coupled to the crown wheel at all times. The other wheel *may* do MORE of whatever the system is doing at the time, but not less. If it is placed under a load that attempts to make it do less, it will become the coupled wheel.

This is best understood from two different perspectives – internal and external.  

Internal and External Perspectives.

External

1. When you turn a corner the outside wheel has to speed up and the inside wheel slow down. The system is driving, so no wheel is allowed to spin slower than the crown wheel. The inside wheel takes all the drive load. This unloads the outside wheel allowing it to do more (go forwards) freely – it uncouples and free-wheels forward.
2. When you come off the throttle and start to engine brake downhill the situation reverses. The crown wheel is trying to slow the car. The load will transfer to the outside wheel. The inside wheel, going slower (more of that the crownwheel is trying to do) will uncouple and freewheel.
3. In a straight line both wheels take the load, but neither is locked. The load actually is applied varied between the wheels, but the flex in the suspension, axles and tyres evens out the uneven power to deliver what feels to be equal torque to each wheel.

Internal

1. The principle of operation is actually simple. A pair of drive rings are forced outward into the side gears (or outer dog clutch in some models) engaging with them and forcing them to rotate. It is not locked here, it is just that both wheels are being driven. A key point to note is why they are forced outward. The cross shaft in the middle of the diff bisects the two drive rings. They have an elongated hole for the cross shaft to sit in. This results in a portion of the rotating torque being transferred into a strong outward force – pushing the drive rings into the side gears and holding them engaged. Think of it as a wedge splitting a log – pushing the rings apart from each other. There is also a very weak set of springs to assist the process, and some dowels to keep the two rings nearly rotationally static in relation to each other.
2. Now lets turn a corner. The inside wheel tries to slow down, and the outside to speed up. The fixed coupling of the side gear stops the inside wheel from slowing, so it starts to take all the power. The outside wheel is speeding up and becoming unladen, as it wants to go faster then the crown wheel. When unladen the outward force on that side drive ring is reduced to near zero. There is another angle manufactured into the dog clutch teeth. This angle is steeper than the one in the cross shaft. It will exert LESS force inwards than the cross shaft exerts outwards, but the principle is similar. Now that there is no outward force from the cross shaft bevel, the side gears slide over the beveled angles on the drive ring forcing it inwards against the very weak springs. This allows the outside wheel to “cam” freely forward. The outside wheel is freewheeling, the inside is driving. I could do this on my Hilux using my little finger, it takes almost no force.

The “clicking” sound from these diff’s is the dog clutch engaging and disengaging. It’s normally only audible in closed spaces like carparks.

The often commented on dog clutch teeth that are not undercut are designed to be that shape. This shape is what provides the force to uncouple the dog clutch. When driven this is overcome by the shallower cross shaft angle, forcing the clutch to be engaged.

The weakness I can see with the system is that the engagement depth with the side gears is very shallow, and on the tips of the teeth – not their strongest part. On the other hand it is engaged the full length of every single tooth – far more than the 2 or 3 teeth under load normally in a diff. I believe that under the right shock loadings it would be possible to catch the diff in a partly engaged scenario and tear the tips off the teeth, although I haven’t seen it done. The best way to do this would be vicious bouncing of the wheels transferring load side to side. Smoothly driven I never had a problem.  

The issue if the inside wheel driving, but the outside wheel braking does result in some rear axle steer under throttle transition. It is evident partly as bush compliance moves the axle, and partly as a slight understeer effect. I noticed it mostly with the large throttle movements from cruise control on winding roads. In a long wheelbase Hilux it was not noticeable under normal conditions. I never had a problem with it towing trailers on steep roads.

In the wet there is an increased propensity to spin up the inside wheel, BUT and this is a big BUT, only to the point where it was going as fast as the outside wheel, then they both drove out of the corner. There was never any significant loss of traction toward oversteer.

I could never see any reason why tyre wear would increase. The unlocking is so gentle I could do it with my finger. The inside wheel would do more work, but the outside less, and as I go around as many left as right corners, this wasn’t a problem.

Documents like these mislead people (since removed) about how mechanical lockers work. After my experience with ARB airlockers, I know I would prefer the mechanical in the rear.

There is long discussion on mechanical lockers here, but you’ll need to read it a few times to catch all of the details.

My personal preference is an AWD car, with a Torsen LSD in the centre and electric locking. A mechanical locker in the rear and a Torsen in the front, preferably with electric locking over the top. Unfortunately I can’t buy this combination.

NOTE: In the diagrams below clearances and angles are exaggerated for clarity. The actual cross shaft hole is eccentric rather than triangular. The side gear teeth slots are a much closer tolerance to reduce lash.

OK – so it’s not real fast, and I am real lazy. Pumping up tyres, bending, checking pressures, inflating still, checking again etc. It’s all too hard. A faster compressor would help, but I prefer the Shell digital auto inflator thingy – drive up – attach – tyres are set. So simple.

My solution, no matter what the compressor. Go to your local air supplies or hoses and fittings shop and buy the 2nd smallest regulator they sell, with a matching gauge and any adapter fittings you need. You’ll spend $50 – $60.

Attach it to your ARB or whatever compressor you have that has a small tank and cutout switch – it needs those, but if you run air lockers, you already have them.

When you want to inflate your tyres, set the regulator to the desired pressure – clip the hose to tyre one. When the compressor cuts out, you know it’s time to detach and move to tyre 2. No checking and standing round. I do it whilst having a coffee and giving the kids a break after hitting the blacktop again.

I could put in a huge tank, but unless it’s big enough to inflate 4 tyres without the compressor then it’s not going to help, as when it depletes it will slow the remaining inflation time to the same as not having a tank at all.

I had the lockers installed 6 months ago when the front diff was broken as it seemed an opportune time. This was my first chance to really test them out in anger, and I planned to have some fun getting into places that were normally too rough or steep to attempt.

Next day I merrily headed down a track I wanted to explore and knew needed lockers and luck to get back up. Imagine my suprise when half an hour down the track I hear the compressor kick in and not stop – oh oh – air leak.

Investigation showed the rear diff breather venting air madly, making me happy that at least it worked as opposed to blowing out diff seals and oil. Under the bonnet had oil spraying out the solenoid, meaning oil and air were definately in close contact – something not in the ARB design.

A quick re-wire to engage the front locker first, and a bit of luck that meant the rear locker was actually still engaging despite the leak meant I could get home, cursing the complexity of the system all the way. A mechanical locker would never have these types of problems.

Mr ARB came to the party and fixed it under warranty, blaming the ARB dealer / installer who had since sold his business. When pressed for details they muttered about a broken copper line, however the oil flowing back up the line pointed instead to a failed seal. They wouldn’t discuss it any further except to cover their ass.

Who was at fault? I’ll never know. It does go to show however that the Legendary Air Locker is not without it’s bad points, in my case the significant risk of a 10km walk back to help.

My vote is with the Lock-Rite or Lokka for simplicity and therefore reliability.

When reading articles in magazines, I see this statement all the time: “We broke a shock absorber” and then remarkable stories of welding it up with batteries or bubblegum.

Myself on the other hand have never broken a shock absorber. Not in the rally car, not on Cape York corrugations, not playing silly buggers at Ormeo, not whilst breaking diff’s, not whilst launching 4wd’s or race cars airborne, not whilst towing heavy loads, not whilst hot, cold etc etc. I have tried good factory shocks, worn out crap factory shocks, Monroe’s, Koni’s, Bilsteins, Old Man Emu, yet none of them have broken. Get the drift.

Let me introduce you to the poor underappreciated Bump Stop. You see, when a suspension system reaches the limits of it’s travel, up or down, it has to stop. If it stops gently, all are happy, if it slams hard, steel on steel, something may give. If it slams hard time and again, fatigue will make sure something will give. Most importantly, in MOST cases, shock absorbers are NOT bump stops. Even if they are uprated “I have a bigger piston than you” shocks, the mounts still aren’t built like bump stops. Something will break.

Here are the general scenarios:

• The very common – shock is too long when compressed - it will become the bump stop over large bumps – Very Bad (Broken Jeep again Adam?)
• If the shock is too long when fully open, the spring will become free and will rattle / may fall out – Kinda Bad (and really irritating isn’t it Mr AdNic)
• The other not so common scenario is a really long stiff spring and a short shock. In this case the spring keeps trying to extend, but the shock stops it early. It is common for the shock to limit the downward travel and act as a bottom bump stop in Live Axle vehicles, but a really long spring or heavy spring will overload the normal behavior - presto – broken shock. The spring free length should only be 10 – 20mm longer than the shock, just enough to keep it captive.

Aftermarket suspension suppliers are generally very quiet on this particular topic. Trying to get numbers is next to impossible. Even the Internet discussion groups are generally ignorant or won’t discuss the travel numbers for their vehicles.

Well here are the numbers for the rear of a 100 Series Landcruiser. The rear suspension design is apparently not the same for the IFS and Live Axle vehicles. Mine happens to be a HZJ105 (live Axle) fitted with Old Man Emu aftermarket suspension. In these pic’s I am in the process of swapping the Old Man Emu OME863 rear springs which were too high / stiff for my use, with a set of King Springs KTRS-70.

All measurements are shock measurements from centre of pin to base of top mounting plate.

• Full Droop, no springs, no shocks, sway bar  – 640mm
• Full Droop, no springs, no shocks, no sway bar  – 640mm
• Fully Compressed, no springs, no shocks, no sway bar  – 400mm
• Full Droop, King Springs, no shocks, no sway bar  – 655mm
• Full Droop, King Springs, OME Shocks, no sway bar  – 640mm
• One side Fully Compressed, King Springs, No Shocks, no sway bar – 505mm

The following pic’s document and explain the above some more

  
 
Fully Compressed on bump stops. The cruiser is a great candidate for polyairs looking at this pic. I normally don’t like them as cars with the bumpstop inside the spring will have heavily limited up travel trying to compress the bag to zero size. In this case the bag would only be compressed approx 50%, making it highly effective at carrying additional load whilst not stopping travel (other than the increased spring rate).

Exhaust touches when on bump stops. Toyota got things very tucked away up there. The panhard rod is just above the horizontal. Lowering the mount would significantly equalize the Left – Right travel of the diff. The panhard rod ideally should be at horizontal when the suspension is at rest.

Sway Bar still not horizontal at full compression. There is some discussion that sway bar mount extension will improve wheel travel. Disconnecting it definitely improves side to side flex, but the actual design in itself does NOT limit down travel. The numbers above prove that. Note the upward direction of the bottom control arm, but the downward slope of the sway bar.

 
Full droop is limited by control arm bushes. (shock is disconnected at bottom). Diff is hard to RHS from Panhard Rod. Note the top control arm angled to the right and the large angle on the panhard rod. The compliance of the upper / lower control arm bushes are limiting down travel. A longer panhard rod would reduce this effect. The axle would spring back up to this spot even when pushed down further.

Same pic on the RHS. Not the top control arm angled to the right.

One side (LHS) only carrying full rear weight with King Spring. The RHS is at full droop. The vehicle is empty. When I first did this test with the jack the front LH wheel was on the ground taking some of the weight. To test it properly, you need to have the car on just the opposite wheels. These springs are possibly a little soft, but I plan to install polyairs. I would like to see about 10 – 20mm clearance from the bumpstop here.

So it looks like in a 100 Series, suspension droop is limited by the bush compliance. This is loaded by the panhard rod. The rod works in an arc, and in the case of the Landcruiser, this arc is mostly downward  below the horizontal. This effect is to move the diff significantly to the right as the suspension droops. As the rod is working at an angle most of the time the bushes are pushed to one side only, binding them, and limiting travel.

The next mod for me will be a panhard rod drop bracket. You could extend the rod, but this is simply patching the problem. Lowering the body mount point will still leave it up out of the way, but make the arc work above and below the horizontal. This will reduce the effect of the Left / Right movement and keep the dif closer to the centreline for longer. Presto, less bush stress and more travel. There is some discussion on effects on roll centre’s. When I know more I’ll update.

These results mean the factory sway bar setup does not limit droop. Whilst I would disconnect it off-road to get maximum flex at the rear, it is the panhard rod / control arm bushes that limit droop. No need to make crop brackets yet.

It looks like Mr ARB / OME has his shock lengths pretty well perfect. I was quite surprised. I am not normally an OME fan, but have been quite impressed with them in this vehicle. Acceptable on road, great off road. The maximum free droop is normally 640mm in and that is the length of the shock. This keeps the spring captive, but within 15mm of the end of its travel. A slightly longer shock would give slightly more travel, adding lever effect over the axle, possibly another 20mm at the tyre. The compressed length is less then 400mm, so they aren’t acting as a top bump stop and going to be damaged.

Now all I need is for someone to try the same with the front. Cmon guys, give me some numbers. I don’t have an excuse to do the front yet myself.

If you are looking at aftermarket suspension you can use the above to determine if what you are doing is of benefit. There is no point in going for longer shocks that 640mm unless you drop the panhard rod a bit, or force the bushes with longer springs. If the compressed length exceeds 400mm, you need to extend the bump-stops. Now I just have to figure out how to flex up like the rear of this Rangie.

The High Beam bulb in my cruiser is a 9005 HB3, Low beam 9006 HB4. These can be swapped with a HIR 9011 bulb that is very similar in design. A small plastic tab needs to have about 3mm of plastic trimmed to fit in the socket.

I purchased mine from www.finemotoring.com in the US who has plenty of information on HIR bulbs. The bulbs arrived in about 10 days, and I found the service prompt and friendly.

HIR bulbs are brighter than conventional Halogen bulbs, including the high output types, and cheaper than HID. I went for them as they are on instantly (HID needs to warm up),  cost effective, simple drop in, no ballast to mount, and I wanted to see what they were like. There is also less legal concerns running these bulbs than HID’s, but I’ll skirt that issue as it seems to be somewhat murky. Headlight and vehicle modification legality debates are contentious at best.

The HIR’s  draw 65w, meaning there is no need to re-wire the car to get a reasonable voltage to them. Running 100W or 130W halogen’s requires re-wiring in most cars. Failing to do this gives a significant voltage drop through the loom, and low voltage at the bulb. Halogen’s hate low voltages very quickly falling in brightness. A 130w bulb underdriven will produce less effective light then a well driven 55W. I have rewired the headlights in several previous vehicles, but am getting lazy in my old age. I haven’t measured terminal voltage to check the amount of loss, but with the engine running and 13.8v at the battery, they seemed fine.

The bulbs that I removed where Silvania 55w units of unknown age. There was no visible material deposited on the glass and the filaments were in good condition, so I would estimate their output to be well within 90% of new. Bulb’s tend to lose output as they age. High beam doesn’t get as much use as low beam, likely contributing to their good condition.

ARB and IPF are flogging HIR as the next best thing, with prices to match. I don’t know where they are sourcing theirs from, and some of their information seems contradictory with other sources on the web. Well, that’s this new intertechnoweb thingymajig for ya.

Fitting was moderately easy. The sockets for the bulbs are tight and tend to hold dirt, with difficult to remove plugs. They are also require removal of the battery to access the sockets, and lifting 35kg of AGM battery out of the tray is great fun.

The outcome is “acceptable”. The light is whiter and brighter, but not hugely so. These are not HID output colour’s or levels. The photo’s don’t give a good comparison as the camera light metering affects what you see. I would estimate the increase to be in the realm of 30 – 50%. Due to the lens design it doesn’t throw the light that much further, maybe 10 or 20m, but the fringe regions are more clearly lit, and the colour is less yellow, probably about 300K whiter at a guess. The centre area’s have more white light in them, but were acceptable before. There is some colour difference when projected onto the garage door, or when you look at them, however the camera doesn’t capture it. They are NOT blue or purple to look at.

I would score them about 6/10 – acceptable as a quick, simple cost effective upgrade with more, but with the falling price of HID kits, I think I’ll just go HID in everything.

 
Low Beam – Conventional

High Beam – Conventional
(Landcruiser keeps Low Beam lit when High is on)

High Beam – HIR Bulbs

Then along comes 2007, eBay and the advertising below: “UNVEIL THE NOBLE’ SGASEITY, DISPLAY THE KING’ DEMEANOUR” How could I resist? I love dodgy asian translations to advertise stuff. It was the above eye catching statement that made me decide this had to be the best HID offer on eBay. Oh, and it was the cheapest. The guy said he was in Australia, but the excessive postage cost and long delivery time seemed to put some doubt on that fact. The ratings on the account were good, and the product arrived OK, but he did cancel his account 2 weeks later. Dodgy? I’m still not sure. I did order and pay for extra High Tension cables, and had a longer 12v wiring loom supplied instead, but this could be simple mis-communication.  

So I am now the proud owner of some shiny kit to fit the shiny Hella Rallye 4000’s that came with my cruiser. I went with 4300K (the lowest colour temp) bulbs after doing much research across the web. It’s not a pretty purple colour, but far bluer than a normal Halogen. Whilst it might look cool, blue is very hard to actually see anything by, especially in dust or bad weather. That’s why fog lights are yellow, it penetrates more, and reflects less. I know in the rally car, in bad dust, you could see more with the driving lights off. White light reflects badly. Dull yellow headlights work best. 4300K is not yellow at all, but it is very easy to see by in good weather.

These are 35W units, the most common. There are some suppliers out there with 50W units. After testing, I don’t need the 50w units, these are fine. For those that aren’t aware, colour temperature has NOTHING to do with brightness. There is a large range of what people call “white” light. It is measured in degrees Kelvin. It is based on a block of pure carbon being heated in a vacuum. As is gets hotter it starts to glow. The actual temperature of the carbon is used as a reference to the colour it is glowing, from dull red (1500K), to yellow (2000-3000K), white (4300 – 5000K) , blue (6000K) and purple (7000K) as it gets hotter.  I decided to put them into the driving lights for a number of reasons

1. If they play up it’s no big deal
2. They take 30secs to warm up – not ideal in normal headlights
3. I want these for LONG range, and the driving lights are for that purpose
4. I did always want those Hella Predators

All required equipment and safety gear

I was not impressed when I pulled the Rallye 4000’s open and found that they were NOT watertight. They are designed to shed water, but there is no ring seal, and no seal near the bulb. The sealed electrical connection at the rear becomes a bit of a waste. So much for the overpriced driving lights. The Lightforce 170’s I put into my brother’s Jeep were far more waterproof than this.  I have had some comments from a friend with one that the reflectors don’t corrode like many lights, even with cracked glass, but I still prefer mine sealed. I was further unimpressed with Hella pricing a replacement lens within $20 of the cost of a whole new light. At $220ea for a light, no clear lens protectors and no reasonable replacement cost, that’s just rude.  I put $40 Lightskinz on mine, having been happy with them before. They don’t collect dirt like normal clear plastic protectors.

 
 I was rather impressed with the top quality silicon High Tension leads, and the silicon rubber seals on all the electrical connections. Cheap chinese perhaps, but very well presented with a high quality feel.  You can see the standard halogen vs the HID bulb. It looks like they simply change the plastic base for the bulb, and keep the capsule the same. When you buy them you generally have a choice of colour temp and base style to suit you vehicle and preference. The short High Tension leads are a problem. You need to put the igniters/ballast unit close to light, possibly where it will get wet. I would prefer well back in the engine bay. Oh well, have to see how waterproof it really is. Mine is mounted inside the bullbar. You can’t extend these leads easily, as they may carry 6000V+ to fire the bulbs. That needs special connectors and insulation, like your spark plugs.

 
The HID Bulb is slightly wider than the standard glass envelope. This makes it a touch fit in the Rallye 4000’s. I am still concerned about the touch fit becoming a break fit when things get hot, but seems OK so far. Ideally I should file the glass reflector a little with a dremel or something, but can’t be bothered. You can see the silicon sealant Hella uses doesn’t go 360 deg around the socket. The reflector is upside down in this pic. It’s only designed to deflect the water, not handle submersion.

 
Round plug (seal) – Square Hole. Bugger. Oh well, silicon fixes all ills, and it’s out of sight when on the car.

 
There are lots of comments on the web debating how HID’s may not work with normal reflectors due to the light coming from a ball as opposed to a filament, or not being at the focal point. They may be correct, but seems to work OK with these lights, and I suspect with most others. You can see the actual glass ball within the main capsule.

 
HID on the right, standard on the left. You can see the colour comparison. Real colours are hard to capture with a camera as the brightness throws it’s metering out badly. Regard it as comparative as opposed to qualitative.

 
HID on the left. I would estimate at least double the standard brightness, and close to triple. The standard High Beam on the outside looks very poor in comparison.

 
Slightly longer shot. The beam is fuller over a larger area, and far more intense.

 
Now for the acid test. This is standard Landcruiser High Beam. That is a 55w low beam and 60w high beam both operating together.

 
Add HID – presto – we have daylight. Again the camera changes it somewhat, but to get the best idea look at 3 things.

1. Colour – far whiter light
2. Distance – You can see the end of the street
3. Spread – that 1/2 circle is very bright in real life.

I don’t particularly love the spread of the Rallye 4000’s – it’s too narrow. They need another pair of spread beams. That said, I had a single Rallye 4000 spread beam with a 100w Halogen in it, and you couldn’t tell the difference with it on / off to the normal headlights. They need a set of spread beams with them. My plan is to HIR the high beams and HID the low beams. That may give me enough spread light to supplement the spotlights. Once warmed up they stay warm for several minutes, so dipping your lights for passing cars doesn’t mean a significant time without bright lights. It takes about 20 seconds from stone cold to get to full brightness. Even when warming up, they produce light, probably as much as a normal headlight, but you notice the difference compared to the photo above.

Conclusion

Rallye 4000 Spots: I don’t particularly love the spread of the Rallye 4000’s, or their waterproofing. I’m tempted to eBay these and buy Lightforce.  - Not recommended 3/5

Chinese HID’s: I do love the 4300K H1 HID’s. I’ll advise how they go in the long term, but for now – highly recommended. 4/5 until I trust them.

http://www.safari4×4.com.au/80scool/george_couyant/diffs/diffs.html

Summary: If you own an AWD car – AWD should stand for Any Wheel Drive – Any wheel with the least traction will get all the drive. The centre diff button just turns it into a “normal” “traditional” 4wd, that is one front and one rear must lose traction to stop going forward. This happens on many hills and is the reason pressing this button doesn’t do that much more to where you can go.

Plenty of water at Burrows Waterhole – this surprised me. The toilets are getting pretty full, the ranger plans to build new ones.

Red Rock Gorge track in good condition, no problem for soft roaders.

Reedy Creek track in poor condition – similar to Rat’s Castle.

Rat’s Castle road in usual condition. Soft Roaders need not apply. Standard Nissan Pathfinder managed the loop, but be prepared to use plenty of right foot.

“The side road” Mr Robert made so famous with his snapped axles, 10 snatch strap, 4 vehicle recovery is in fair but overgrown condition. I got down and back up OK, but had to drop tyre pressure to 24psi and use full lockers. Lots of flower fluff in the radiator. You really should have a winch to do this road just in case. There are no big steps at the moment, but plenty of very very loose shale. I followed it through to a creek and nice waterfall that was dry. 500M further along there is a steep climb that would be rather nasty and is *supposed* to bring you out to an open gate near the track. I know the gate, but didn’t try the hill as my rear locker chose that moment to blow a seal. There are two side tracks I sw off this one, but didn’t have time to investigate. One is *supposed* to lead to the old mine.

Casualties – sliced a sidewall on my Cooper AT’s. Slice 45mm long repaired by sending away to be vulcanized – $30. Doing the side road without a spare was nerve wracking. Slice was from a rock corner cutting along the sidewall bulge. Normally my sidewalls fail from pinching between rock and rim, so this is a new one for me.

Spoke to the ranger and he said the old road from Rats Castle down to the south end of the park was destroyed in the ‘76 floods. Someone tried it this Easter and ended up smashing a diff or similar judging by oil stains found by hikers. Apparently there are 30 – 40 river crossings and it is not passable. Maybe with a few extreme cars w/ 35’s, winches, lockers, shovels and chainsaws it could be opened, but this would be rather frowned upon. Chainsaws being banned and it being a National Park.

Plenty of wildlife. Saw the usual Deer, Grey Kangaroos, Pretty Face Wallabies, Goats and heaps of bird life.

Great place, great food, great people. It was a good trip.

Soft roaders can manage it – but need help. They were happy for me to help with towing the trailer, but not so fussed on letting us sleep in it….

Rats Castle circuit is a little rough

OME articulates better than I thought

 
Burrows still has plenty of (cold) water

 
This is a view most won’t see of “the hill”. Bring Lockers, and a winch, and axles for any Discovery’s in your party.

My goals were as follows:

1. Seperate battery for starting
2. Maximum capacity for Aux items
3. 80Ah Useable Capacity
4. Option to expand to triple battery setup for winching

I’ll go into a debate on battery system choices in a seperate article, but to meet my needs I chose the following:

Odyssey PC925 – Small Start Only battery
These small expensive AGM’s are made to deliver spectacularly high starting currents from a small battery. If you don’t have room for a Dual Battery setup, or want to go to a Triple setup, then one of these should be your start battery. 925A for 5 secs, 620A for 10 secs – it starts my 1HZ with ease. I’ll update after a -5 winter day, but for the moment it works fine. I didn’t want a huge start battery that never used more than 5% of it’s capacity and wanted to be able to go to a triple setup later.

Fullriver HGL-120 – Aux Battery
These chinese AGM’s seem to be getting great reviews. Ultra low internal resistance means fast charging. AGM commentries are all over the web. The main things that are important to me are:

1. Fast Charge
2. Good resistance to deeper discharges
3. Great vibration resistance.
4. Adequate Capacity – 80Ah is easily acheiveable from a 120 rated batt

You’ll find out why the AGM costs so much and has higher capacity when you try to lift it. 35Kg as opposed to a conventional N70ZZ at 21 – 25Kg.

Piranha 150A Isolator – Conventional Voltage Sensing Isolator
It came with the car and after bodgy repairs to the cracked plastic case and corroded PCB tracks, now works fine.

Fitting the batteries

The Fullriver comes with an unusual terminal – basically a recessed nut and supplied bolt. You can either take off your conventional terminal and use theirs, or do as I did. Cut the lead terminals off your deceased battery, drill them to fit the bolt though – presto – conventional terminals in case you need to swap back for some reason.

To fit in the landcrusier cradle you’ll need to remove the plastic tray underneath. It’s not big enough and makes the battery sit up too high. I can’t see any reason for it’s existance, as the paint underneath is rubbed anyway, and it doesn’t have a drain making acid protection pointless.

You’ll also need to modify the rear “hook” bracket. It is too short and wont go over the slightly taller battery. 2 minutes with an turbo torch had it red hot and rebent. There is enough length in the bent peice hook to straighten and rebend it as a longer straight shaft.

 
Odyssey TEMPORARILY mounted in original position. This one battery replaced 2 batteries triple it’s size. Plan is to put it in the rear of the engine bay on a small tray. No need to move fuel filters and less weight.

Clearances are tight, but it fits. Modified terminals can be seen.

Modified rear hook mount needed for additional height. You can see the tight clearances.

Comments:

Conventional Wet cells don’t have enough useable capacity for my demands. Deep cycled they die.

Conventional Deep Cycle cells are slow charging. I doubt I’ll have the engine running for long enough to charge them fully.

I have concerns about AGM’s and heat. All Lead Acid cells have a positive feedback cycle when charging. ie, the hotter they get, the more current they adsorb, making them hotter, making them adsorb more current……
Normal wet cells will outgas if this gets out of hand, and you get to top them up with water. AGM’s recombine the gases, releasing more heat. This can be bad. 50deg is the theoretical max, but that is also said for conventional cells. Most people get away with it, some don’t .Ideally, mount them inside the vehicle. Personally, I’m going to put an aluminium heat shield in to keep the worst of the radiator heat from blowing on them, and rely on their forward position to feed them cool air. Some people do nothing and have no worries. Others have problems.

The isolator – like 90% on the market simply parallels the cells when the input voltage hits 13.6v. Many claim all sorts of wizardry, most are simply relays in a black box. 

In an ideal world every cell would be managed independently, and batteries would cover all our needs. The reality is that we have to make do with  differing solutions and varied information.

Some of the best battery information is here, here and here

This guy also has great information.

The general rule is that deep discharges shorten a Lead Acid batteries life. Cells not built for this are damaged very quickly. My experience has been that an average brand name 12mth old battery flattened by headlights overnight is basically stuffed and won’t carry more than 30% of it’s new capacity. It’ll start the car fine with this shallow charge, but that’s it.

The goal of an isolator system should be to
a) Leave you able to start the car
b) Minimise deep discharges of any battery

Now we come to the point of most arguments discussions. In most cases people opt for separate batteries, one for starting and one for auxiliary use. This means that the requirements the batteries face are not the same, and often differing batteries are chosen for these tasks. Further, as they are subjected to differing conditions they age independently and often will be replaced at different times. Yet the manual that your isolator came with, your mate on the Internet, and quite a few battery manufacturers will be telling you “DO NOT PARALLEL BATTERIES OF DIFFERENT CONSTRUCTION / SIZE / AGES”. That’s it. The discussion never moves beyond that point. There are HUGE debates on forums all over the Internet, yet they can’t get beyond this point. Series string construction and management is discussed ad-nauseam, yet the classic 4wd warning remains. Luckily for us, they are WRONG.

Evidence, More Evidence, even More Evidence

Parallel what the hell you like, it won’t matter. Which is lucky, because MOST expensive battery isolators do just that, and have for years. They all claim to be magic in a box, but most are relays, something known about for a little while now and use in all sorts of places.

Battery Calcs & Types

The calculations below are based on what I phrase “effective capacity”. This varies depending on battery type and it’s use. I’m going to assume you have it in a 4wd and drive a 2 – 4 hours a day when on trips. The numbers below are based on not wanting to flatten the battery more than 80% and it’s likely state of recharge from a normal alternator (your mileage may vary). You can roughly work out your effective capacity as follows.

1. Starter Battery
   (0.4 * RC) * 0.8
   =approx 48Ah for N70ZZ batt
2. Deep Cycle
   Ah * 0.5
   =approx 50Ah for 100Ah batt due to common low state of charging.
   This *may* be better if there are very long charge times or high charge voltages.
3. AGM
   Ah * 0.8
   =approx 80Ah for 100Ah batt due to fast charge capability.

Remember – these are for NEW batteries – it only gets worse as they age. Ageing depends on time, temperature, cycles and depth of discharge.

Isolator System Types

1. Parallel / Single Battery
   Works well enough, if you don’t discharge it too far. If you do discharge it you’ll be stuck looking for a jump start. Auto cut out devices and voltage monitors are a good solution. It’s also the cheapest up front solution – no parts needed. You’ll not be game to discharge your batt’s below 70% effective capacity if you want to start the car, so your capacity is:
   0.7
   * “effective Ah rating of battery type”
   * 2
   =Useable AH
2. Diode Isolator
   These are generally regarded as inefficient. Jaycar has one here. They induce a 0.6v drop across them. According to Odyssey this is the difference between fully charged and 50%. What will happen is charge voltages are high enough that losing 0.6v means the battery will charge 30% – 50% more slowly than normal, and possibly not charge fully. Theoretically a solid state MOSFET solution would work well, but I haven’t seen one yet. Relays are cheaper I guess. You only get one battery so the rough calculation is:
   AH = 0.7 * “effective Ah rating of Aux Batt Type Only and a slow charge”
3. Voltage Regulated Isolator
   This is the most common solution. Redarc is the most obvious (no box), but Piranha’s black box of tricks is the same thing. My black box fell to bits and inside it’s just relays connecting the batteries. They work by isolating the batteries when the voltage drops below a set point – around 13v. When the primary battery is back above 13v due to the engine running, it reconnects them. They generally should build in a bit of hysteresis (damping) to stop is short cycling if the voltage is close to the cutoff. The calculation is:
   AH = “Effective Ah rating of Aux Batt Type”
4. VR Isolated with Lower Cutout than Cut-in.
   Traxide does this really cool VR Relay isolator. By setting the cutout to the mid 12v, it lets you use 50% of your primary battery. Normally in an isolated system there is this huge heavy main battery there for just starting. I find this a waste. If I can use 50% of it’s capacity safely, then I would prefer to do so. The calculation for this system is:
   AH = (“Effective Ah rating” (Aux)) + (0.5*”Effective Ah rating” (Main))
5. Independent Management
   Now we get to the tricky (read expensive) stuff. To fully manage all batteries to their maximum potential all batteries (and ideally cells) need independent attention. People that live on solar or independent power often take inordinate care of their batteries, or alternately buy batteries that last 50 years. For 4wd use this means independent charging. There are a number of ways this can be achieved from vendors such as Rotronics, Amplepower and Arrid. Temperature compensation is one of the most important components, but they also regulate charge voltage, pulsation, float test etc etc. Nice stuff, but be prepared to pay for it. It may be cheaper for the casual user just to put new batteries in every 2 – 3 years, but if you live off it, then your use would probably justify the extended service life.

Personally I work out the following.

Battery & Isolator Cost and Capacity Calculator Spreadsheet

My Waeco CF50 uses *about* 3A @ 50% duty cycle * 24Hrs = 36Ah/day.
Add a couple of 8w flouro’s (1.5A * 3Hrs) and maybe the radio = about 45Ah / day.
I often want to stay 2 nights in the one spot, so I want nearly 2 days supply.
80 – 100Ah is enough for what I need.
The cheapest system that can deliver that is a Normal Start Battery + an AGM with a Traxide isolator.

There is a spreadsheet attached here that works out approximate the economics and capacities of each system. If you have unusual requirements or conditions, then the numbers will have to be tweaked a bit.

Interestingly the cheapest setup that also gives the most Ah/$ is simply a pair of normal Start batteries in Parallel. Unfortunately 67Ah useable is not enough capacity for my needs. $4.50/Ah

The most cost effective for my requirements is a normal Start battery + an AGM with a “Tricky Voltage Relay” by Traxide. 104Ah and $5.30/Ah

The very common Isolator + Deep Cycle solution works out to about $11.0/Ah – not very cost effective.

Results surprised me slightly.

http://www.lizardlegs.com.au/blackrat/news.asp

Unfortunately for most 4WD owners, this is exactly what we want to do. Even if they are exactly the same using an isolator makes them do different jobs, so when you go to charge them they are no longer the same.

95% of battery isolator systems charge your dual batteries in parallel. Even the ones that claim to be smart – are just a set of relays (switches) inside to parallel the batteries together. (There are some EXPENSIVE exceptions, you’ll know already if you have one).

Luckily it seems from some expert commentary on the topic it is actually just fine. I figure this guy should know what he is on about, seeing as he is now the current Chairman of the IEC subcommittee on Secondary (rechargeable) Batteries. Primary batteries being the Duracell use once variety.

Acticle 1

Article 2

So isolate or charge in peace, parallel is fine.

A far more interesting discussion is optimising charge management, but that’s another discussion.

OK, here it is simply. If you own a Toyota 4WD, whatever the version, and want the rear LSD to get you out of a really nasty spot offroad, do NOT, EVER use the foot brakes to help. I know it works in Hummers, I know it helps to lock up the rear LSD, – Still DON’T, not even gently. The front diff will tear itself apart. You can use the handbrake all you like (Toyota handbrakes are only for decoration, they don’t actually do anything), but don’t use the foot brakes.

The brakes are biased to the front, and the front brakes are larger the rear. When you are on Low range with an auto, the rear brakes will always slip first, this puts 100% of the torque into the front diff. Guess what, it’s smaller than the rear, and defiantly won’t cope, even with moderate braking. If it’s an IFS Cruiser, it only just copes with normal driving.

Yes the brakes lock up the rear LSD and that helps you out, but you’ll smash so much in the process, you’ll be stuck anyway. Use the handbrake all you like, if that doesn’t work, you are stuck, sorry.

FYI: Mine is a HZJ105 with the “stronger” live axle and larger front diff. Still not tough enough.

Sick of the pathetic fuel range in your Surf? I get around 400km to the standard tank with the 1KZTE 3L Turbo Diesel. 450 on the highway, 250 towing a car trailer. After following mates that get over twice that (I hate Land Rovers), I decided to fix the problem. I think it was Toyota’s decision to give the new Prado (same engine) a massive 180 litres, compared to my 55 litres that finally clenched it.

The mega $$$ for the aftermarket tanks was out of the question, although their capacity is definitely excellent. I had seen a guy with a patrol tank in before, and it seemed to fit well. He had a filler under the wheel arch, a solution I found unacceptable. So a sat down and figured out how to make this all work, without a body lift.

Warning

Note: Fitting an additional fuel tank may:

• void your 2nd hand warranty (it’s not worth crap anyway)
• void your insurance
• leave you legally liable
• make your vehicle unroadworthy
• make your vehicle unsafe
• be illegal
• sag your rear suspension
• affect your vehicles handling
• be a fire hazard
• explode

So, if any of the above happens, or anything else happens due to this information, tough luck. It worked for me, but may not for you. Maybe I got lucky, maybe this is the Internet and I am lying to you, maybe I want to blow up all Surfs, maybe I am smarter than you, maybe it’s all an evil terrorist plot (and another place to hide weapons of mass destruction). So, you do it, your problem. All liability absolved. Lawyer types will disagree I am sure, but it will do for you and me.

Click here to leave this corrupt and decadent western imperialist travesty of a site

I decided to follow the Landcruisers that I had dealt with previously and run dual tanks with a changeover switch between them. The option of a pump though system that filled the primary tank occurred, and the pro’s and cons are listed below.

• Parts Req’d

• GQ Patrol / Maverick Wagon Fuel Tank (complete with pickup) ($90 from wreckers)
• 1.2M x” Filler Hose (Hydraulic Suction Hose was cheapest)
• 1.5M x” Filler Overflow Hose
• 3M x” Fuel Supply Hose
• 3M x” Fuel Return Hose
• 2 x Landcruiser changeover valves (80 Series GXL Diesel) ($50 from wreckers)
• Mounting Hardware – Nuts, Bolts, Washers, Locktite, Rubber
• 45? filler bend (x” Exhaust pipe)
• 120? filler bend (x” Exhaust pipe)
• 300mm Exhaust Pipe
• Hose Clamps (Various)
• Wiring, Switches etc.

The patrol diesel tanks do not have an in tank pump, as they are suction from the injector pump on the engine. The surf is the same. If you want to do a transfer system you will need either an external pump, or a different pickup.

The hose lengths above are for an install the same as mine. If you choose to different valves, mount them elsewhere, do a pump through setup, etc, etc, you will need different quantities. I chose the cheapest fuel hose I could get, and used hydraulic / fuel suction hose for the filler. It was actually cheaper than radiator hose, and much better rated. It has a large spiral wire inside, so be careful when cutting it. This also makes fitting it onto larger / smaller hoses quite difficult. To fit it to larger hose, lubricate well with oil and push hard whilst rotating it. It will expand slowly and go over. Use only good quality hose clamps to compress the hose. Good quality hose clamps are sturdy stainless, and have large indentations for the thread, not holes in the strip.

The changeover valves are quite difficult to remove from the Landcruiser. The wrecker won’t like you very much after this. They are in the rear up above the rear axle. I don’t recommend doing it yourself.

Costs

• Tank – $90
• Hoses & Clamps – $120
• Valves – $50
• Misc – $50
• Exhaust – $50
• Compliance – $75
• Total $435

Step 1: Line it up.

Two people make this MUCH easier.

Note the fuel stain. I thought this was from a leaking drain bung. Big mistake. Turns out the spot welds for the internal baffles have started to crack. It’s very small. but enough to leak. Bugger.

Step 2: Trim Exhaust and Chassis

Not as scary as it looks. This allows the sender and pickup to sit up in the chassis and give about 1″ more clearance under the tank. If it bothers you too much give it a miss. I preferred the clearance, and just rust proofed the cuts well. I actully didn’t have to trim this much, but it doesn’t really matter. Structural strength is no different as the towbar is much stronger than this stiffener.

Most exhausts will be in the same place as the tank. Time to move it.

Exhaust pic with tank in place

Step 3: New Exhaust

I took the Surf and tank to the local exhaust guy (Ian Diffen) and had him make up a new rear section. I requested mandrels due to the tight bends required, although the rest of the system is just press bend. 90? and over flow better if they are mandrel due to much less compression of the pipe. Under 90? will cope. He had to trim the mudflap to get it where I wanted it, but it clears the tank well. It is actually a tad close to the wheel, but doesn’t touch, so it will be fine.

Note: It makes using the LHS tow point difficult. You may want to work it a little different to allow for that.

Step 4: Modify Tank

Using object of choice (I like a rubber mallet) and a friend, fit the tank where it will mount and find out the high spots that will touch, then lower them
A bit of judicious thumping at this point gives another 15 – 20mm clearance under the tank. Also give the filler a good touch up till it is more horizontal, rather than the 45? it normally sits at.

Step 5: Front Mounts

I used heavy threaded rod for these. It doesn’t provide a huge amount of lateral strength, although more than I would credit after lining it all up. I used Locktite on all nuts, although NyLocks would be as good. Definitely use some retaining method, as fixing it later could be difficult. The threaded rod was just drilled through the flange in the rear cross member.

Hints:
1. Line it all up well before drilling
2. The rod is different lengths
3. Stay out on the flange, otherwise nuts won’t fit as they hit the cross-member.
4. Yes I had to bend them once they were in, the flange is not horizontal.

Step 6: Weld in rear mount bar

I welded the rear mount to my towbar. Don’t have one, you’ll just have to figure out something else. I’d recommend fitting a towbar to help protect the tank.

Step 7: Rear Mounts

Three high tensile bolts in the rear with rubber to allow a little flex. (Yes it is the old timing belt)
These also provide most of the lateral support.
If I was doing it again, I wouldn’t trust my welding and would have bolted this support bar in. Butt welds have a habit of cracking as the chassis flexes. I am still considering options for this, but it seems to be ok for the moment.

Will update if it falls out

Pic of both front and rear mounts

Step 8: Mount Tank

Curse and swear till the tank is mounted in place. Definitely another two person job.

Hints:

• Use 2 people
• Use Locktite or Nylock nuts
• Connect supply and return hoses before mounting
• Connect wiring for sender before mounting
• Block off vent hose as tank will be vented through filler to other tank and it’s emissions system.

Pic of installed with hoses attached.

The clear hose for the diff breather you can see is just temporarily tucked out of the way.

Step 9: Filler Hose fitting

I used a 45? piece of exhaust press bend to assist in this spot. I tried without it and it was just about impossible. It’s still not easy. You’ll need to lubricate the fitting on the tank. The pipe has wire inside, so persist, it will go on. As you wriggle it, the wire moves round till it fits. Make sure it is well on, as there will be flex, and this may pull the hose off if it is not well attached. Persistence will pay off.

The filler line runs forward and just fits between chassis and body in the triangular gap at the edge. I moved the wires for the suspension that run through the same gap more to the centre so they didn’t fowl the hose. The hose will get some abuse as the body and chassis flexes, but it is very tough, and should last the life of the car. There is no sharp edges through the gap.

Step 10: Modified Filler

I stole this idea off another Surf member who had similar under his. <insert link here>

Mine is a little different, as I don’t have the body lift, clearance is an issue. I came out at 30? with a piece of exhaust pipe, and them chopped and welded it parallel to the current filler. I also drilled and welded the filler cutout pipe.

I tried using the 80 series tricky changeover valve system, however there was no way to make the cast valve assembly fit. Even with alloy welding and machining it would be quite difficult. This fits, although it is quite tight.

The new filler fills the original tank, with the factory filler going to the new rear tank.

Another filler pic.

Step 11: Connect the Filler Hoses

This is a very difficult job. Be prepared to swear. There is a 120? elbow under the red circle to get around the tight bend. Take your time, it will work. I had to stretch a few things, and it was a bugger to re-bolt, but it will work. There is virtually no clearance so it is very tight work. It would be Much easier with a body lift.

The extra clear hose is my rear diff breather.

Hints: “Tap” the lip on the body away a little to give more clearance. I found a large flat screwdriver and a hammer made a large difference. The sharp edge of the body is a lot less of a problem when folded flat. You won’t get it all, but the bit to the rear near the elbow will definitely move. Means that you can get to the hose clamp on the elbow.

Make sure this hose clamp is on properly, it’s hard to tell. Otherwise when you go to fill the tank, it’ll pour fuel everywhere. Been there, done that.

Step 12: Changeover valves

The valves that come from the cruiser are a nice 3 port type, with 2 inputs and a common output.

They are a slightly larger fitting than any of the other pipework. I ended up using a little oil on the hoses, and heating them up with a hot air gun to get them to fit. This was after much swearing. A diesel doesn’t care about a little oil in the hoses.

Hints:

• Connect wires before mounting
• Lubricate and heat hoses. Careful using too much force as valves are plastic.
• Be careful that hoses, valves and wires will not fowl on suspension, diff or brakes.
• Diff will only go up so far, look at you bump stops to get an idea.
• Check which ports are what on the vales first. There is 2 inputs and a common output. Connect the wires across a 12V battery or charger to actuate the unit. I used unpowered from the original tank, and powered for the new supply.

Another hose & valve pic

I spent ages working out where to mount the valves so they would fit, not be near the exhaust, not fowl the suspension, not go though the floor. I ended up mounting one from the front lip of the rear cross-member. The return valve was mounted to the front lip of the tank with it’s bracket inverted.

And another

Step 13: Connect Hoses

This is where the factory hoses fit on. Send the original tank lines back to the changeover valves. Connect your new lines here.

Hint: Use the factory springy hose clamps on the fuel tank as there is no way to get a screwdriver in to tighten normal ones.

You may have to prime the lines, but mine did it itself. Make sure that you put fuel in the second tank before trying to run on it. If you suck the system dry, you will have to prime it all again, and that’s not fun.

Clearance

Rear View

I think the clearance is quite reasonable, up to your personal opinion.

We took it out to some pretty rough terrain and it was nowhere near to rubbing the ground.

I would like a bash plate under it though. Not too heavy, just something to adsorb any pointy rocks I may come down on or rub over. Similar to the factory fuel tank protector would be fine. I’ll keep looking.

RHS View

LHS View

Results

• Filled it with approx 80 litres of diesel, gives about 75L useable. I’ll confirm when I have a gauge and it stops leaking.
• No gauge, but it was still going at 500KM
• I estimate range will be 1000km now or more with both tanks full
• When it’s empty you don’t know it’s there
• Full, it lowers the back of the car a bit. Mine sits slightly high in the rear unloaded, and slightly low loaded for camping. That is with H/D Kings in the rear. Now when I fill the tank, it sits as if it had a full load on board. I would NOT recommend fitting this with standard springs. Full tank and full load was still quite reasonable rear ride height, just slightly below neutral.
• Handling is virtually no different, full or empty. Little heavy in the rear like a full camping load.

Comments

• These tanks have a bash plate on them in the Patrol. Mine didn’t for some reason. I’ll have to get one.
• I’d normally leave it nearly empty as it is more weight to cart around, this will impact fuel economy, tyre wear, handling etc.
• You obviously can’t mount another spare tyre under there
• The after market tank with 120L would be nice, gives more useable than this one does. Weight and cost a lot more though.
• The after market 110L replacement tank would be better, but is a lot more money, and give less range than this. It is really only an additional 55L on top of factory, where I now have 80L. Ideal placement for additional tanks is between the axles though. Out on the overhangs is a bad place to put weight as it de-stabilises the car. Tanks, bullbars, winches, water, batteries are the heaviest, and always end up out on the overhangs, a really bad combination. Try and minimise this where possible. Store water and jerry cans in the rear footwell for example, it’s central and low.
• I’d use the rear tank up first when going off-road, so as to take weight out of the rear. This will lift the rear a little, and improve weight distribution.