Part-time 4WD conversions offer a range of benefits. Let’s check out what goes into an install

PART-TIME JOB

WORDS BY LUKE BRAND PHOTOGRAPHY BY HOLESHOT IMAGES

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Part-Time 4WD ConversionsDRIVELINE

1 Before you lob in, make sure you know the exact build date and model of your Cruiser.

You’ll also need to consider a few extra bits you may need, like transfer gaskets, oil seals and oil. Make sure you talk to Marks, so they can guide you through the process and anything extra you’ll need. The kit comes with all the mechanical components, but you will need to buy a centre diff lock switch from Toyota

2 While you’re clean, do the work inside the truck. You’ll need to fit the centre-diff lock

switch into the dash loom (this is different depending on your model). When installed, you acti-vate 4WD by pressing the diff-lock button, and simply moving the shift lever to high or low – no new levers are required!

3Step one underneath the 4WD is to remove the rear tailshaft form the vehicle,

drain the oil from the transfer, and remove the speedo cables. Next is to remove the rear exten-sion housing of the transfer, and the circlips that hold the intermediate housing into place. Inside the extension housing is the viscous coupling – this is no longer required

4 Pay special attention to where all of the shims and spacers fit – Mark recom-

mends you label everything as you go, especially the bolts that are all different lengths. Tap the housing off gently so as not to separate the input shaft – if this comes out, you’ll need to replace the seal

5 The next job is to remove the centre-diff rear spool (held on by 12 bolts). Be careful not to

remove the actual diff centre – just the spool

6 Now you can remove the pinion shaft, locating pin, pinion gears, rear side gear

and thrust washer. These parts are no longer needed. Make sure you leave the front side gear in place – it supports the front output shaft

7 You’ll need to press the tapered roller bearing off the old spool, so you may need a

workshop to help here. Make sure you clean up all the parts, and fit the bearing to the new spool sup-plied in the Marks kit

8The roller bearings are hugely expensive to replace, so en-sure that you are careful when

working around it

9 The new spool can now be fitted back on the front case. Apply some grease to the

nylon thrust gear bush to prevent it grabbing

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If you own an 80 or 100 Series LandCruiser, chances are it’s fitted with full-time 4WD, and chances are you’ve at least once wondered if there’s a

way to get around it. As a major marketing feature on every model bar the DX and Standards, full-time 4WD is great for icy on-road conditions. But, for what we 4WDers do, part-time engagement is the way.

Proving that good old Australian engineering always finds a way around what the Japanese expect us to believe, Marks 4WD Adapters developed a part-time 4WD conversion kit for such LandCruisers some years ago. Not only is it one of the most popular 4WD conversion kits worldwide, it delivers real benefits (and savings) to the owner in a short period of time. Manufactured from top-quality components in the Melbourne facility, the part-time kits are a snap to fit, and a job any competent DIYer can do at home.

So why fit a part-time kit, we hear you ask?

Firstly, by not having the front driveshaft, differential and axles spinning, considerable wear is prevented, as these components are only needed when 4WD is actually required. Spinning these redundant components increases fuel consumption, and testing has shown that up to 15% can be saved by simply disengaging the front half

of the driveline. This is especially important if you’re doing lots of miles cross-country. If your LandCruiser uses 15L/100km loaded, it’s costing you around $20-$25 every 100km in fuel alone. A 15% saving could represent anything up to three or four dollars less in that same distance – which adds up to a thumping $750 saved on the average yearly fuel bill!

Apart from the wear and tear on the driveline, tyre wear is also prevented, as there is less driving torque being screwed to each corner of the vehicle. The on-road manners of the vehicle (particularly the torque steer-prone 80 Series) is greatly improved, especially if you’ve fitted larger rubber.

When we caught up with Marks 4WD Adapters’ very own Mark French, he was in the process of fitting a part-time kit to a spare transfer case he had lying around. While the article shows the transfer case external to the vehicle to demonstrate the steps clearly, in most cases the job can be done with the box still in the vehicle. You’ll need a good set of tools, a proper torque wrench, and it’s advisable you always have a workshop manual on-hand before you pull anything apart, but if you know your way around the tools then this could be a DIY install. Let’s take a look at what’s involved!

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Part-Time 4WD ConversionsDRIVELINE

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CONTACT DETAILS

MARKS 4WD ADAPTERSPh: www.marks4wd.comOr phone:(03) 9702 7366

MARK’S TOP DRIVELINE TIPS• Buy the correct workshop

manual for your vehicle – and use it in tandem with the fitting instructions

• Use a quality torque wrench, and follow the three-step tension process carefully

• Use a soft hammer when separating alloy housings and tapping components

• NEVER engage the centre diff lock switch while moving - it may damage internal components

THE ABS ISSUERigid (live) axle LandCruisers that were fitted with ABS brak-ing (IFS models aren’t a problem) encountered an issue when retro-fitted with a part-time 4WD conversion kit. As the ABS sensors required the front axle to be spinning to provide information on exactly what the wheels and brakes were doing, unlocking the hubs disables the ABS and illuminates the ABS fault light.

The good news is that Marks Adapters have now developed a fix for this issue, which should be available by the time you’re reading this article. The fix works by relocating the sensors to a point on the wheel hub – meaning ABS operation is not affected by the conver-sion. If you own an 80 or 100 Series live-axle LandCruis-er, do yourself a favour and give the team a call, because there’s no downside to a part-time conversion!

COSTSThe conversion kit for an 80 Series retails for $585.00 including a set of AVM heavy-duty freewheeling hubs, whilst the same kit including hubs retails for $655.00. The final touches are being put on the new kit to relocate the ABS sensors and prices may vary slightly to reflect manufacturing costs. Still, that’s less than the fuel you could potentially save in a single year, so this is truly a modification that pays for itself!

10 Apply the correct Loctite to the bolts and re-install as per your workshop

manual. Marks recommend you follow the manual’s procedure and use a quality torque-wrench. It’s done in three stages to ensure everything is correctly tensioned, so it’s important you get it right!

11 Here’s the new spool fitted and being tensioned

12 Re-assembly is a reverse of the pull-down. Make sure you use the proper

oil-grade sealant when re-install-ing the housings, and grease up the shims and spacers to keep everything lubricated. Do not rein-stall the viscous coupling, as it’s no longer required. Once the speedo cable and tailshaft are re-installed, you can fill the transfer with oil – Marks recommend 75w90 grade, and you’ll need about 1.5 litres

13 The next job is the hubs – remove the dust cap and axle-end circlip. Once the

six nuts are off, remove the hub end to disconnect the axle and hub from each other

14 You can now install the new AVM hub – if you haven’t by now got a soft hammer

in your toolbox, go and buy one! Re-install the six bolts, and tighten as per your workshop manual

15 Before you pop the circlip back on, check the model of your 4WD. Mark says that

pre-1992 models may need the 8mm wide spacer (in the kit) installed. The final step is to fit the free-wheeling hub selector using the star-key bolts.

16 It’s as simple as that! The install will take a work-shop around half a day to

do – and home users will knock it off in a day. You can now select 4x2 on your hubs, and leave the centre diff-lock switch off when driving on road. Just like 4WDs used to be!

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THE SAVINGS COULD ADD UP TO $750 A YEAR!

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Part-Time 4WD ConversionsDRIVELINE