Good used diff

[ck_carnut]

Where is the best place to get a good used diff? The last 2 I've replaced seem to last only about 50K miles before they get noisy, and I'd rather not be replacing these things every 2-3 years. The current one seems to need output bearings, and I'm not sure I'm up to rebuilding it myself.

Thanks.

-=Chris

[DesktopDave]

They're all a gamble, the two I've replaced were limited-slip units but they never seem to do any limiting...

I'd considered getting one rebuilt with a functional LS unit, but that gets pricey.  The parts are cheap but the services are expensive.

[DesktopDave]

I also used a medium case diff donated from a 325is...the small case isn't as durable.  It's a straight swap, but finding something as high as a 4.10 would be difficult (I think only >88 auto 'verts had them).  I used a 3.73 and IMHO it's an improvement over the 4.10.

When I bought mine the input seal failed, ruining the input shaft bearing.  I pretty sure that grinding diff was the reason he decided to sell it.  I might have been able to rebuild it, but decided to replace it instead.

From the PO's records my car is on her third rear-end.  I'm hoping the heavier medium case lasts longer.  I pulled it from a car with 167K miles and I've put 20K on it since, no problems yet.