Thread: Patrol Diffs

Expense. Can't find any Landrover diffs under $600.

It can be done as it's been done before. $2000? Highly unlikely. What will cost $2K? The only things I will need on top of the complete diff housings are calipers. Everything else is fabrication, which I can do.

I know the rear of the GQ is in the centre, hence my question about the linkage. The suspension will aso be raised about 2" above what it is now, so I think I can make the mount for the top linkage sit on the pumpkin rather than beside it like it is now.

Like I said, I have access to an engineering shop, so tail shaft modification won't cost anything.

I believe the biggest part of the job is removing the Nissan brackets and welding on the Rangie ones.

What about the glorious Department of Transport and their regulations?

Originally Posted by Not_An_Abba_Fan

I know the rear of the GQ is in the centre, hence my question about the linkage. The suspension will aso be raised about 2" above what it is now, so I think I can make the mount for the top linkage sit on the pumpkin rather than beside it like it is now.

And here is where your problem is "The GQ is in the centre". There is a reason that gearbox/transfer cases are aligned verticaly in automobiles. I will say all of them but in fear of being proven wrong I will say 99.999999% of them. There are some very important relationships (well beyond my ability to explain) that this alignment does to help prevent vibrations. You will find this rear offset will most likely vibrate the crap out of the majority of tailshafts you use. The other issue is the cente mount on the diff pumpkin puts your A-frame at a wierd angle to and stuff the rear suspension geometry.

One thing you could try as the diff flange is in the centre of a GQ the pumpkin is actually offset is to flip the axle 180 degrees around the pumpkin to try offset things correctly to the side you need. It might just work, other than that an 80 rear works better or offsetting the pumpkin itself to align with the transfer case properly.

Having said all that the front is fairly "easy", then all you need to worry about is the whole engineering thing.

Originally Posted by Not_An_Abba_Fan

After successfully munching 3 diffs in the rear of my '89 Classic after fitting 33" tyres, I have decided to put GQ Patrol diffs in her. I know the Disco diffs are an easier fit, but I can get front and rear diffs for $350 for the pair, where as the Disco diffs are $600 each. I also believe the GQ diffs are one of the strongest 4WD diffs you can get.

Is there anyone here that has done the conversion? How did you go about the rear linkage? Did you keep the 3 point on the rear, or did you swap to the Patrol 4 point?

How did the brakes work afterwards? Did you have to swap master cylinders or do the Patrol calipers work fine off the Rangie M/cyl?

Also, the pinion angles, is it better to set them up parallel from diff to transfer at ride height? Or should they be a few degrees off like factory?

I have access to an engineering shop so the finer points of fabrication aren't an issue. Such as tail shaft modification. On that note, I have read that a DC tail shaft should be fitted to eliminate vibration as the rear tail shaft will run at an angle from the centreline of the vehicle. I have four tail shafts so I was contemplating fabricating my own double uni set up off the transfer.

I will hopefully get the diffs next week so the modification should begin very soon. I will try and put up progress pics as well.

This has been done a couple of times, Maggot did this and wasnt happy so subsequently pulled it out and ran a LandCruiser rear which worked. AS far as I know people cant get them to stop vibrating due to the offset pinion/transfer. I'm not sure if anybody has tried a shaft with 2x double cardins though.

The cheapest and easiest way would be to run a Salisbury though if everything just lines up and bolts up (excluding propshaft) and then your wheels go back on. A day in the garage rather than a few in the workshop.

Note the ratios in the Patrol are different to Rover also.

If you do fab in the Patrol rear, you can use a Salisbury A-frame mount plate to accept the ball joint and then fabricate something on the housing to bolt this down to.

Remember that on top of all the time and fabrication you will have to get the car to an engineer as what you propose is a major drive line modification. That will cost somewhere around the $500-1000. Sure you could skip this but then your insurance will be invalid and then there's the cost if you do tell them.
I get it that you just want too, and if you can, go for it. But I think all told it would be cheaper to do the Salisbury swop and you at least know that it will work.

Cheers, Nino.

Slight hijack - though it may help the OP - but with the Salisbury swap if your new axle has drums I assume you just hook up the brakes and that's it? Obviously discs would be nicer, but I just happen to have a very old drum-braked axle under a rusty 110.

Originally Posted by Davo

Slight hijack - though it may help the OP - but with the Salisbury swap if your new axle has drums I assume you just hook up the brakes and that's it? Obviously discs would be nicer, but I just happen to have a very old drum-braked axle under a rusty 110.

Im not sure, but I'd expect youd also change over the brake master cylinder etc too.