Changing Gtr Rear Diff Ratios

[chaos_GTR]

Hey guys, struggling to find some infomation about putting 3.5 or there abouts diff ratios in my GTR diff. So story goes I have a R32 GTR rear diff in my 180sx with a 2 speed glide with a KAZZ 2 way diff center fitted. It currently has 4.11 stock gearingit and im wanting to put around the 3.5/3.6 in it. I have access to a R34 GTR V-SPEC active LSD diff which is 3.5 ratio. Now my question is will the crown wheel and pinion from that fit into my R32 GTR diff? Or any other infomation about going to a lower diff ratio would be MUCH appreciated

Thanks.

[Duncan]

ahh good question....not sure.

I do know the 34gtr front diff gears do not fit in the 33/34 casing/sump, but I am not sure about the rear.

Can you get the diff casing as well as the centre?

[KiwiRS4T]

ahh good question....not sure.

I do know the 34gtr front diff gears do not fit in the 33/34 casing/sump, but I am not sure about the rear.

Can you get the diff casing as well as the centre?

You sure about that Duncan? You have written 34GTR front diff doesn't fit in the 33/34 casing - surely it will fit in the 34 casing? I have an R34GTR front diff waiting to go in my R33 sump and have just been looking out for an R34 non V spec rear diff to go with it - I know some R34 GTRs over here have put R33 diffs front and rear to lower the gearing so I have always assumed that the reverse was possible.

[GTSBoy]

I think there is a good chance it won't fit. The Nismo GT-Pro diff price list expressly says that their diffs do not suit the active LSD types. That would suggest to me that there is a lack of commonality between the pumpkins and the CW&P sets.

People who have swapped non-active diffs into V-specs have generally put the whole diff in, case and all, yeah?

It would seem obvious to me that if the OP has access to the V-spec diff, that he should obtain it, take it apart and see if the CW&P will bolt to another R200 centre (surely there's one lying around that you can access). If it will do that, then it will fit your diff too. Oh, unless there's also some difference in nose length or whatever that might also cause trouble, but you should also be able to check into that upon dismantling the diffs.

[Duncan]

You sure about that Duncan? You have written 34GTR front diff doesn't fit in the 33/34 casing - surely it will fit in the 34 casing? I have an R34GTR front diff waiting to go in my R33 sump and have just been looking out for an R34 non V spec rear diff to go with it - I know some R34 GTRs over here have put R33 diffs front and rear to lower the gearing so I have always assumed that the reverse was possible.

You know, there are so many wrong things in my post that maybe I should stop drinking and typing. The correct statement is:

r32/r33 ratios (4.4 and 4.1) will not fit in the r34 front diff casing (3.5).

I know you've said it has been done, but they must have either modified the casing or used the 32/33 casing/sump (they bolt on the block fine). The 32/33 crown wheel/centre is too large for the 34 casing.

[R31Nismoid]

People who have swapped non-active diffs into V-specs have generally put the whole diff in, case and all, yeah?

Correct

Although it's more then point that Nismo do not make a GT Pro to fit a Vspec A-LSD... So it requires a swap out with a non-Vspec.

At least that's with a R33.

[Piggaz]

Correct

Although it's more then point that Nismo do not make a GT Pro to fit a Vspec A-LSD... So it requires a swap out with a non-Vspec.

At least that's with a R33.

I just did this conversion two weeks ago. I also needed shafts AND my V spec bolt pattern did not line up with the flanges that Nismo supploed in the kit. Both were a 6 bolt pattern but not the same size.

[R31Nismoid]

The shafts you don't need if you have the linkage between... I forget the technical term, it's a separate part. The shafts are actually the same once outsite the connecting bit (IIRC)

[Chris32R]

How sure are you on this? I bought a brand new R34 GTR sump/diff and was going to fit my crown wheel and pinion and lsd centre from my R32 GTR front diff into it.

I had no idea that the casings were different between models

You know, there are so many wrong things in my post that maybe I should stop drinking and typing. The correct statement is:

r32/r33 ratios (4.4 and 4.1) will not fit in the r34 front diff casing (3.5).

I know you've said it has been done, but they must have either modified the casing or used the 32/33 casing/sump (they bolt on the block fine). The 32/33 crown wheel/centre is too large for the 34 casing.

[Duncan]

Yep that is exactly what I tried. The casings are different.

[Chris32R]

Yep that is exactly what I tried. The casings are different.

I have just done a search and the part numbers for R32 and R34 GTR front sump/diff casings are the same (3842003V00).

I might give fitting it a go and I'll report back with how it goes

[KiwiRS4T]

Please do report what you find - I have a diff swap planned and would like to know how you get on!

I have just done a search and the part numbers for R32 and R34 GTR front sump/diff casings are the same (3842003V00).

I might give fitting it a go and I'll report back with how it goes

[Chris32R]

Will do. I should get my sump back from

Getting an extension next week and then it's straight to the diff shop to install the 4.11 gears hopefully.

Edited June 10, 2013 by Chris32R

[chaos_GTR]

Ive done a look around and found that S15 manual with helical cut diff is the exact same part # as a GTR with diff centers and it has a 3.6 ratio. Any idea if the crown wheel and pinion will work in my gtr diff?

[KiwiRS4T]

Might work in the rear but where are you going to get a 3.6 front?

[GTSBoy]

He doesn't need it. This GTR diff is in an S chassis car.