Clutch Slip Perentie 4x4

[john.k]

A while ago I used one of these plates in my Leyland Terrier,when the original clutch plate disintegrated.I wondered why the Rover plate had a big recess machined into the spline.It seems the crank of the Jappa has a big spigot sticking out.By the way ,I used a second hand plate from the army scrap I used to buy,so net cost was zero,a figure to suit my budget.I still wonder if the reduced spline would cause a wear issue.In my opinion the size of the plate is marginal with a 4cyl /4 liter engine,and I would expect slip if conditions wernt ideal.A motor that size needs a 300mm/12inch plate.The Leyland has a 4l six.Regards John.

[Dervish]

I wondered why the Rover plate had a big recess machined into the spline.It seems the crank of the Jappa has a big spigot sticking out. ... I still wonder if the reduced spline would cause a wear issue.In my opinion the size of the plate is marginal with a 4cyl /4 liter engine,and I would expect slip if conditions wernt ideal.A motor that size needs a 300mm/12inch plate.The Leyland has a 4l six.Regards John.

The matter revolves more around the 4BD1 having a flywheel housing (flywheel shy of bellhousing mating surface) and the LT95 being designed for a more conventional engine (flywheel proud of the bellhousing mounting surface). The spigot adapter necessarily reaches out from the flywheel to reach the gearbox input shaft, and of course the friction plate has to have offset splines to reach the flywheel as well. The splines on the friction plate aren't compromised - i.e. they're designed that way - so I don't think it is a concern in terms of spline wear.

I've heard speculation that the 4x4 Perenties used a low-but-sufficient clamping force pressure plate so as to reduce fatigue on the driver and give a more manageable pedal. Once you up the power it's no longer sufficient; but in my experience the HD (i.e. high clamping pressure) clutches are a silver bullet for slip. It isn't necessary, but there appears to be plenty of room on the flywheel for larger clutches - if someone wants to get creative.

[303Gunner]

I've heard speculation that the 4x4 Perenties used a low-but-sufficient clamping force pressure plate so as to reduce fatigue on the driver and give a more manageable pedal.

That's an unusual way to engineer a softer pedal feel. The clutch master cylinder is the same as many trailer hydraulic cylinders, and there are available in the same physical dimensions with various bore sizes: 7/8", 1", 1 1/4" etc. It would be a simple matter to fit a heavier clutch pressure plate, but then to go to a correspondingly larger master cyl and retain the same clutch slave cyl. A change in the pivot dimension of the clutch pedal would be needed to give the same pedal travel with reduced travel of the Clutch Master push rod.

[Dervish]

I've heard speculation that the 4x4 Perenties used a low-but-sufficient clamping force pressure plate so as to reduce fatigue on the driver and give a more manageable pedal.

That's an unusual way to engineer a softer pedal feel.

I agree, but here we are. As Brian said, the only difference between 6x6 and 4x4 clutches is the pressure plate. Even better than playing with hydraulics and pivot points would be to install larger diameter friction and pressure plates - more torque capacity with the same clamping pressure and longer lasting clutches to boot.

[Philthy]

This is the clutch kit supplied to the ADF in my neck of the woods. The diaphragm is 1.7mm thicker than the Land Rover part.

[Philthy]

On installation, I replicated what I found when disassembling the clutch. The plastic retainer is secured in the fork hole only by a bonding agent. See arrow. Not in any manual I've read but makes sense.

[Philthy]

There is a plastic clip that retains the pushrod to the fork that is prone to snapping on installation so I was told.

With the warning from the parts supplier I was given a spare one just in case. So, I warmed it up in a glass of water in the microwave and it went on easy as. I repeated the previous "insurance measure" used being the cable tie around the clip for the future.

Used Sikaflex 227 to waterproof the bellhousing, starter motor and the clutch slave cylinder. Reamed the housing breather vent while I was at it.

[stephendavis]

Ross just wait until to have to reverse a big trailer into a tight spot, you will wish that clutch to hell just ask me I know LOL cheers Dennis

I always use low range when reversing with a trailer as if I see someone riding the clutch I will have a go at them