Dual transfer cases give you the ultimate in offroad low gearing.

Reduction gears in the transfer case alone are nice, however there are many times when you miss having your normal 2.28:1 low range, such as beach driving, driving between trails, and also in short course winch style events where high range is too fast and reduction low is too low. Dual cases fill the gap in allowing multiple low range ratio’s depending on your configuration.

The concept of dual transfer cases for the Hilux was invented by Marlin Crawler in the early 90′s and since then they have continued to revise and innovate the concept, bringing you the best adapters in the world.

The front portion of the Hilux Transfer case is basically a 2 speed gearbox, it is this section you use in conjunction with an adapter that allows you to bolt the low range portion of a transfer case in front of a full transfer case effectively doubling your low range gearing.

Used in conjunction with reduction gears in one of the transfer cases you can end up with 20 forward gears! You have your normal high range, normal low range, reduction low range, and reduction x normal low range.

Used with stock gears in both transfer cases you end up with 15 forward gears, normal high range, normal low range, and double low range.

Here’s some crawl ratio’s for a Hilux with a G52 5 speed gearbox and 4.56:1 diff gears.  The stock 1st gear ratio of a G52 is 3.92:1, stock transfer gears are 2.28 and the most common reduction gear set is 4.7:1

So Crawl Ratio = 1st Gear x Transfer x Diff

4.56 Diff Gears standard single case = 3.92 x 2.28 x 4.56 =40.75:1

4.56 Diff Gears standard dual cases = 3.92×2.28×2.28×4.56=92.92:1

4.56 Diff Gears dual cases with 4.7:1 reduction gears in one case = 3.92×2.28×4.7×4.56= 191.55:1

4.56 Diff Gears dual cases with 4.7 reduction gears in both cases =3.92×4.7×4.7×4.56= 394:1

In looking at gearing options for our Blue Hilux – Weekend Warrior Project we decided dual transfers would be the most versatile solution. The rig is going to do some trail work, some beach work, and will be running 4.56:1 gears and 33″ tyres. Reduction gears in one case would be a bit of overkill, so we decided just to go with 2 stock 2.28 gear sets.

It’s probably worthwhile talking a bit about the 2 different kinds of transfer cases you are likely to find in a Hilux, as this is an important part of the build. The old school gen 1 lux’s from 79-83 have a 4 speed transmission and behind it a “top shift” transfer case. The late 83 through 97 solid front lux’s have a 5 speed transmission with a “forward shift” transfer case.

The difference between these two transfer cases relates to the shifter and shift rail location. The earlier model top shift transfer cases have the high low shifter mounted in top of the transfer case and no shift rails protrude forward of the case. The later model forward shift transfer cases have the shifter mounted in the tail housing of the transmission and the shift rails protrude forward of the transfer case. As we are mating up the low range portion of one transfer case onto another full case, the full case must be a top shift transfer case eg no shift rails protruding forward of the full transfer case. The low range portion ie the front case will need to be a forward shift case if you are fitting it to a 5 speed or top shift if fitting to an earlier model 4 speed (and also some auto conversions).

So in short

Rear Case must be a top shift transfer case

Front case needs to be a forward shift for a 5 speed and a top shift for a 4 speed

As the older cases are getting harder and harder to find, Marlin Crawler have designed a top shift conversion kit which consist of shift rails and shift forks to convert your later model forward shift box to a top shift box.

Below is a picture of a top shift transfer case, note the shifter location and no shift rails protruding forward of the box

Below is a picture of a forward shift transfer case, note the shifter is located in the tailhousing of the transmission, and the shift rails protrude forward of the box

Now we’ll have a look at the bits you are going to need to build up your “crawl box”

The first step is to weld some key stock onto the shift rail, the reason for this is the front case is only going to operate High and Low, so we only need the shifter to move back and forward, not side to side.

The next step is to prepare the chromoly coupler. Give it a wash with degreaser to get rid of the machine oil, and apply some assembly lube to the coupler and also the cage bearing, slide the cage bearing onto the coupler.

slide the 2.28 low speed gear onto the coupler.

Place the steel ball into the hole on the coupler

Place the thrust washer supplied onto the coupler

Slide the coupler, low speed gear and thrust assembly into the adapter as shown

Flip the adaptor over and install the supplied circlip to the coupler.

Turn the adaptor over again and install the shift collar, shift fork and shift rail as shown.

Apply assembly lube to the small pocket bearing and place the pocket bearing into the coupler, then install the input gear into the coupler as shown.

Place the gasket onto the adaptor and dress with your favourite sealant, ultra grey works well as does aviation non drying gasket sealant.

Install 5 studs into the transfer case housing as shown, use some blue locktite to make sure they don’t come out.

Place the housing on top of the adaptor

Fit the 2 bolts saved from the donor case as shown

Fit the flat washers and spring washers to the studs as shown

Install the snap rings onto the bearings as shown

Place the steel detent ball, detent spring and detent plug into the right hand side of the housing as shown (the side with the shift rail). Use a bit of blue locktite on the detent plug to prevent it from coming loose.

On the left hand side of the housing install the supplied 2wd/4wd indicator block off plug as shown.

Thats the crawl box done, all that you need to do now is install the 6 supplied studs to the rear case and bolt them both together.

I thought I’d take some pics and provide a little more insight in how to set up our Solid Axle Widening Kit.

The IFS rear axle housing has a wider offset than the stock solid front axle Hilux, and swapping out your rear end on your solid front lux with an IFS rear end is a great way to get some extra width without having to run wheel spacers.

The issue then becomes how to get the solid front width to match that of the wider IFS rear. The answer is to fit a Solid Axle Widening Kit. (This kit is also popular when doing a Solid Axle Swap on an IFS Hilux/4 Runner to get the track to match without running spacers.)

The IFS Hub has a greater offset wheel flange as can be seen in the below picture

On the left is the stock solid front axle hub and on the right is the IFS hub, you can see the wheel flange has a wider offset on the IFS hub than the solid front axle hub.

The main component to the kit is a spacer which fits between the IFS hub and the solid front axle rotor, the spacers purpose is to align the caliper mounting position to the rotor.

Installation is very simple, and here we will look at preparing and fitting the ifs hub to the solid front axle rotor ready to install back onto the solid front axle. We’ll assume we have a solid front axle stripped down to the spindle, and have removed the rotor from the solid front axle hub.

The first thing you need to do is get hold of an IFS Hub. The IFS Hubs bolt to the rotor, so you are best to get the hub and rotor assembly complete as you will need to re use the bolts that bolt the hub to the rotor.

Remove the bolts holding the IFS Rotor to the IFS Hub and give the hub a few taps to set it free, discard the IFS Rotors and give the hub a bit of a clean up, if needed now is a good time to replace the wheel studs, and you may as well replace the wheel bearings as well whilst it is all apart.

Place the IFS Hub so the wheel studs are facing down and then place the spacer on top as shown in the above picture. Use the bolts that originally held the IFS Rotor to the IFS Hub to bolt the spacer to the hub. You will need to give the spacer a bit of a tap to get it on. Put some Blue Locktite on the threads and tighten them up to 80 ft lbs in a star pattern to make sure it aligns itself true. Give a couple more taps and retighten.

Now place your solid front axle rotor on top of the spacer and bolt it on using the supplied socket head caps and the 2 rotor retaining bolts from your solid front rotor. Use some blue locktite and torque up to 80 ft lbs.

All thats left to do is replace the hub assembly back on the front axle, refit the hub flange or free wheeling hub and bolt up the calipers and you have an extra 3″ of track.

They’ve been around for years, cheap reliable traction that is easy to install in your stock open centre. Often referred to as Lunchbox lockers, these automatic lockers consist of 2 bi-directional dog clutches which lock both axles like a spool when torque is applied and when torque is not being applied disengage to allow one wheel to turn faster than the other, which is what happens when you turn.

There are a couple of variations of the lunchbox locker on the market, and I thought I would take some time to show the differences between the old faithful Lockright from Richmond Gear and the new kid on the block the Spartan made by Yukon.

The two lockers pictured are both for solid front Hilux 2 Pinion diff.

The boxes look remarkably different, however once you pull them out of the box, they look almost identical.

Both consist of a driver, a coupler and a spacer and a bag of springs and pins. I put them on the scales and the Lockright weighs 2.1kg’s and the Spartan 2.15kgs.

The main difference between the two is the pin system. The Lockright has smaller pins and one small spring that fits inside a larger spring per pin. The Spartan has larger pins, almost double the size and one medium size spring per pin.

The way you install the pins and springs into the locker is also different, installing the springs into the Lockright you need to use a small screwdriver to seat them into the driver, whereas the Spartan comes with 4 spring retainers allowing you to push the springs into the driver and lock them in, once installed into the carrier you simply pull the retainers.

So there you have it, a basic overview of the difference between the Lockright and the Spartan Lockers.

Happy Wheeling.

It is a common belief in the aftermarket that there are two different 8″ Toyota Ring and Pinions – the “V6″ and the “4cyl”. Whilst it is true that there are two different designs, the name given is misleading.

In actuality the Ring and Pinions that most refer to as a “4Cyl” are simply the thinner 85 and older pinion head design. The Ring and Pinions that most refer to as the “V6″ are actually found in all 86+ 8″ diffs, regardless of engine type. The actual difference between the V6 and 4CYL vehicles is that the V6 does have a different housing and different pinion and carrier bearings.

The above pic shows the difference in the pinion head length between the two types of ring and pinion.

The above pic shows the difference in the bearing thickness between the two types of ring and pinion.

Our main differential supplier, Nitro Gear have superseded the older type of ring and pinion for a number of reasons :

1. The older style pinion head is smaller and offers less material and strength.
2. 1985 is a long time ago and there are more vehicles out there using the 86+ style.
3. Less part numbers make inventory and ordering more simple.

So if you have an older model Toyota 8″ you just need to use the appropriate 86+ pinion bearing when installing your ring and pinion. Toyota part number for the correct bearing is 90366-35044

Info and images supplied by Nitro Gear