rbpwrd240

I was wondering if anyone could tell me which (new) bearings and races they used to install an S15 helical into an S14 case?

Id like to have new bearings and races available when I do the swap and I cant seem to figure out if S14 Bearings will fit or if I need to source the S15 Bearings that most use that are already pressed onto the helical at arrival.

As for the races it seems most people use the S14 diff races so then it stands to reason that I could simply order new S14 R200 races.

Correct?

e1_griego

You're correct. I think all the r200 bearings are the same, anyway. If you do the interchange lookup on rockauto there are a ton of models listed.

rbpwrd240

Cool that's what I figured but I wanted to see if someone that had already done it could confirm it for me.

So.... Hows that Cedric/Gloria Helical? I almost tried to source on of those after seeing your post lol.

e1_griego

That was 5 diffs ago.

Giken 4 life.

rbpwrd240

Nice!!! Did you take out the S15 cause you went to a more track driven setup or did you run into issues with it? Just out of curiosity...

e1_griego

I went to a Nismo 1.5 GT. Then another helical, then the Giken.

I personally don't like the non-linearity of torsen diffs, and with decent grip (baby 245 hoosiers) and decent power, the torsen gets confused.

Giken is very very predictable and linear. Car does exactly what I want.

I actually just put a giken in my BRZ yesterday, too.

rbpwrd240

Good info sounds like my suspicions were correct. You went that route for a better track car. I may run into similar issues as I am planning on running 245/255 staggered tires but with a street tire compound. My car will be a street car that does some track day stuff.

LoSt180

Don't forget S15 ring gear bolts. The S15 had larger holes on the helical, so S15 bolts have a larger shoulder to take up the slack.

rbpwrd240

Yep already got mine coming for those looking they are the S15 ring gear bolts with a 12mm thread and 13mm shoulder,By themselves its a nismo part for changing ring gears on the nismo gt lsd. West covina nissan sells them for 10 bucks a piece. Ebay has them for about the same.

RalliartRsX

The bearings used determine shimming of the diff no?? Wouldn't you just use whatever is already in the case??

That seems to be the common sense solution unless the bearings are fubared (or you want to take it to the a transmission shop and have them correctly set backlash, runout, etc, which costs $$$). At which point, you would measure each bearing (in order as they come out) and purchase a similar sized bearing. If you do not do this, you risk having the gear meshing being off to the point of risking ring gear/pinion failure.

S15,S14 and S13 all use the same diff bearings. Unless the bearings are screwed up, I would recommend you use what is already in your current housing if possible. My understanding, you can't just buy "new" bearings without actually know the size bearings you will be needing to correctly shim (or place) the differential.

e1_griego

The shims determine the diff placement.

I've replaced bearings on every diff I've put in, and then just re-used the stock shims in their original location.

rbpwrd240

^^^This is what I understand from my research as well. You said it yourself Ralliartrsx all the diffs use the same bearings so why wouldn't they all be exactly the same? If you plan on owning the car for a while why would you want to put used bearings back in?

The shims however can be slightly different so it appears from my research.

I plan on getting everything new except the helical and then take it to a shop and tell them to do the swap as well as set the backlash and shims. I don't want the whine that I hear lots of folks talk about that didn't bother to reset the backlash. I may even replace the shims if the shops says I should.

e1_griego

Just put the shims back in the way they come out. That's all it takes.

Croustibat

You'd rather induce understeer with a staggered setup and have issues because of tyre width than just using smaller, better tyres ?

Sometimes i don't understand people. Sometimes i understand them even less.

Just fit 225 or 235 good tyres as a square setup and be done with it. 235/40/17 is the exact same diameter as stock, so it won't rub, won't need (much) fender rolling, cheaper to get, lighter, have less drag, and you can rotate them around. That + a s15 torsen = perfect for a 300-350hp setup.

rbpwrd240

You know what I cant understand....

When people make up theories based on a few comments. Did I mention my suspension setup or why I am running the tires? Also its again not a race car. Anyone who cant tune out some understeer should reconsider how their own car was built. Also my HP Mark is considerably higher then 350hp more like 500whp.... A bit more tire in the rear will probably be appreciated especially on the street...

Now anything to add on the topic at hand?

RalliartRsX

Rethinking, you are very correct! I am actually doing the swap now, and I was referring to the shims as there are varying thickness.

I can measure the S15 bearings and the S13 housing bearings to confirm (they are currently downstairs).

Yep, OP, replace the bearings. If you need part numbers, I can get that for you.

e1_griego

Glad to hear I didn't fuck up my last 4 diffs!