Which Skyline Rear Diff Output Shafts Fit The S15 Spec-R Hlsd?

[GTSBoy]

Dude, I spent well over a grand putting the S15 centre into my R32 housing by the time I'd f**ked around with buying enough diff bits to put it all together properly and had it set up by a diff guy.

Just because the "main" part is cheap when you're talking about the S15 centre, doesn't mean the whole job ends up at 25% of the price. Only that part is 25%, the rest still costs and you end up saving a smaller proportion of the total cost than you expect.

It's like buying a cheap turbo or cheap injectors and then needing resistor packs or adapters and whatever. It never ends up as cheap as you'd hoped.

[TheOne]

I completely understand what you mean, but I'm not sure you understand where I'm at with the diff.

I have the COMPLETE S15 differential and output shafts. I could run it as is with the S13 axles for the time being.

If I can find out if the R34 GTR stubshafts fit, then I would just need the correct axles and hubs (which I can source fairly easy here in the US). I could sell the S15 stubshafts and recoup a good amount of total cost. This all depends on if I can find the R34 shafts.

Someone has to have a set somewhere, or even a junkyard or rebuild shop or something.

[GTSBoy]

Do you know that that housing will bolt to your subframe and you won't have to shorten the rear half of the tailshaft? S15 diff has speed sensor in the front of the diff housing, yes? Adds length yes?

[TheOne]

Based on the research I've done, the S15 pumpkin will bolt to the S13 subframe. It's not a common swap, but I did see a few people say they've installed it into an S14. If it fits the S14, it should fit the S13. I just need to hopefully swap the rear cover with the S13 one.

I do have to either make or purchase the two bushings for the front of the diff since it is missing those. Shouldn't be a big deal.

I do know that the S15 housing is longer due to the speed sensor. As I've said, I'm piecing things from scratch, and need to go with a custom driveshaft anyways to mate the GM T56 transmission with the diff. Shouldn't be an issue.

[TheOne]

If someone here has done the swap with those halfshafts, then I wouldn't be dropping a ton of money on figuring out if things work or not.

It's like how the Z32 brake swap is so popular with S-chassis cars. A few people did it and knew that it worked. Now it's common knowledge and everybody does it without dropping a ton of money to figure out if it works. The power of the internet!

[simpletool]

PRetty sure there would be a spline count difference and a 1mm diameter difference at least. There certainly is between S15 and R34 GTT diffs. I can't see the GTR reverting to smaller diameter output shafts. GTR typically use R230 diffs.

[mitchum]

The S15 Diff uses the bigger spline output shafts like the GTR

I have a stock R32 GTR rear end as well as a US spec S14 rear end with the S15 helical diff installed..

I have compared both output shafts from R32GTR and S15 there within 1-2mm of each other.. measureing from inside base of shaft to C clipe groove.. there are the same spline count/diameter..

When installed into each other they both feel like they engage the C clip in each diff.. Im thinking about using the helical S15 diff and use the GTR outputs for the bigger/better axles.

Edited December 24, 2013 by mitchum

[GTSBoy]

Well....I have an S15 centre with S14 small spline half shafts in it. So it can't all be true.