Hey, just heard from the diff shop and the s4 Turbo LSD diff i am getting shimmed has broken teeth on the crown wheel!!!..

I have a s5 Turbo LSD and a s4 turbo open diff sitting around at home.

My question is, is the s4 turbo LSD crown wheel the same size and specs as the s5 Turbo LSD and/or the s4 turbo open diff? crown wheels? and if so can i replace the crown wheel by itself or do i need to replace the wheel and the pinon its attached to???

cheers.
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On the US spec cars the ring and pinion (what we call the crown gear and pinion) are the same 8 inch 4.1 ring gear for S4 and S5 models, and all Turbo models came with LSDs.

So if your open diff has a 8" gear, it would probably work... but if the open diffs on your turbo use the non turbo 7" ring gear, then no... it wouldn't work.

and your bump as been deleted. Bumps are forbidden here in the 2nd gen tech section.

 

ohhh ok thanx, sorry for the breaching the rules.. my bad.. Neway my car is the GT Limited RX7, comes with a open turbo diff which is as you say has an 8" crown gear, (41 teeth) and the 10 toothed pinion. So yea it worked fine. Although u must keep the Crown gear and Pinion together as they are a pair... I was told this by 2 different diff people, im not sure why this is but yea u cant mix and match.

 

as long as you are not changing the ratio, you don't have to keep the same pinion with the same gear.

The big issue is whenever you take the pinion out, it needs to be re-spaced to make sure that it hits only the middle of the gear. If it is hitting too narrow, or too deep, or off to the side, that is when you will snap off gears and have weird wear.