R32 GTR Diff Mods for Harrison

[400TT]

I know Sambo was asking about GTR rear, well I've dug out the old photos. This info should be just as relevent for R33 rear.

This is a standard GTR rear, not a V-Spec.



Main cradle mounts cut back/modified to fit Harrison. Yeah, those 4 mounts( 2 at front, 2 at the rear) with the big holes that take 22mm bolts. Heavy track use has seen this rubber inserts tearing out even with large washers used, so now they are solid mounts.

Original GTR hollow light-weight swaybar has been removed.

You can't see it, but the front rubber mounts in cradle for diff carrier have also been replaced with solid alloy bushes.

Handbrake cables also done.




The cross-drilled vented rotors are standard oem GTR.

Also notice the bright orange "use LSD oil only" sticker on the rear alloy diff cover. This is the easiest way to be sure the carrier is GTR(mech LSD).




You can see the modified lower shock mounts. This is one of the extra hassles of fitting a GTR rear, it's a lot harder to mount the shocks.

Notice the finned diff cover, not all GTR's have it. I think the later ones don't have fins and I've got a feeling R33 GTR don't.




The rear steer has been disabled. Also the rear carrier mounts which have also been converted to solid as they tore out with heavy track use.


Like my quality paint job. Well I did spend the time and prep it right.

Our Cobra body/chassis has not arrived at this stage of the build.

Warren, you've done this much more recently, did I miss anything? (These photos were taken nearly 5 years ago)

[Jac Mac]

Craig,
Have any problems shown up with extended use of these in Cobras, like CV failure, twisting half shafts, Hub brgs etc. I know its probably a bit unfair given that the previous life in the donor car would be unknown in most cases.

Jac Mac

[400TT]

Diff was untouched by us when fitted to the Cobra just under 5 years ago. Other than mods required to fit it.

Since then my brother has tightened up the LSD and replaced wheel bearings.

CV Joints will be next, but they are still original.

I'm sure that rear-end had a real easy life in the GTR before we got it. Yeah right.

No problems with anything else.

Cobra runs a turbo 1UZFE(Lexus 4lt).

Has done 15,000km's+ on the track over the past 5 years. Competes in Sprints, Hill Climbs, Drags and even a drift event. Regular Drag Test & Tune meets. On a good day does 11.6 sec 1/4 mile on street tyres(not drag street tyres etc).

One thing you can say, is that these Skyline rear-ends are reliable. Not like the Tremec 3550 gearbox that gets regular work done to it due to all the track work.

Other than replacing all the rubber bushed mounts with solid, it's been good as gold. I have just recently picked up another GTR centre as a spare for my bother. The GTR rear-ends are not compatible with the lower model Skylines(GTS-T) etc.

Of course it's been through brake pads and rotors like they are going out of fashion.

We also used Skyline R32 GTR alloy front uprights on fabricated A arms and GTR front/rear brakes.

[Jac Mac]

Thats good to hear, I have picked up a few of these from 300zx for around $150.00 a time, have enough to set up all three cars with spares now. Might go to larger willwood rotors/hats/calipers though. Should see an old fella like me out!

Jac Mac

[400TT]

Yep, they are great value for money even here. Just getting harder to find, R33 is an easier/cheaper model now.

Some great Jap stuff about.

Back brakes have been fine so far. Now running slotted DBA rotors after the GTR ones wore out. The original rotors were stuffed, we actually picked up some other 2nd hand GTR rotors to start things off. So going by rear rotor wear, the GTR rear certainly had some use/abuse.

[WKB]

Craig,
I think you covered everything. Mine was a reasonably straight forward installation. Warwick fitted the K frame while he was building the chassis. This made it a simple bolt in process. Like yours I used big washers to clamp the mounts. I also used these washers as shims to get the tailshaft alignment. The CV joint on the diff was replaced with a flange plate. This was the recommendation from the company who built the tailshaft. The most time consuming job was adapting the alloy uprights to attach the shocks. I used the same spring/shock combo as the front.
Like you mentioned in an earlier thread it is a bit more involved and fitting the shocks can be time consuming.

Warren

[albanycobra]

Hey Craig
Have you got a pic of that GTR rear end in the Harrison chassis?
I'm thinking about a Cobra build after I finish the GT40. I am looking at G-Force at the moment. But I like the idea of GTR stuff over Jag gear.

[sambo]

Nice pics Craig, thanks for those. At a glance my R33 Gts-t diff is pretty similar, but as we know it has a slightly wider cradle (mounting points anyway) and different drive shafts etc. Anyway I was planning to take off my discs and clean everything up on the weekend but that 36mm nut on the end of the axles put a halt to things. Now to find one on the cheap - what a P.I.T.A.

[400TT]

Sambo, just buy a cheap 36mm rattle gun socket(they are black, instead of chrome) and use it with your breaka bar.

albanycobra, still looking for those photos.

[Jac Mac]

Originally Posted by sambo

Nice pics Craig, thanks for those. At a glance my R33 Gts-t diff is pretty similar, but as we know it has a slightly wider cradle (mounting points anyway) and different drive shafts etc. Anyway I was planning to take off my discs and clean everything up on the weekend but that 36mm nut on the end of the axles put a halt to things. Now to find one on the cheap - what a P.I.T.A.

One of the first things I made after buying these rear-ends was make a plate with the stud pattern drilled in it and welded to a piece of 2x2 box section about a metre long, did the same with a 36mm socket, makes loosening/tightening that big nut a breeze. Also drilled a Holden/Vette pattern in the plate so it does double duty.

Jac Mac

[sambo]

Just reading the above notes regarding washers on the cradle mounts... is the thinking that a washer between the cradle and the mounting point on the car will lessen the force on the rubber bush/insert, spread it more evenly, or...?

Cheers

[sambo]

And for those who've tracked their Harrisons... would you consider this type of thing a worthy investment? We all know rear traction is an issue!

http://cgi.ebay.com.au/ws/eBayISAPI....tchlink:top:au