Rear Axle oil ...

[scott 4991]

OK, I admit it, I have NEVER changed the rear axle oil and see in the manual it uses 2 quarts of SAE90. Is this hard to do? I assume a drain plug like the oil I change regularly! (see, I do some maintenance). I will look into this more, but any opinions on how often this oil should be changed?

Thanks

sc

[Blitzkrieg Bob]

if you have an LSD ( look for a S on the tag), then you'll need 140.

Use a good quality synthetic

[bigtisas]

I've never done that either. How often does the axle oil need to be changed and how? Thanks.

[Blitzkrieg Bob]

do it

[brick8]

Real easy, but be careful and use jack stands. The trick is having the right hex socket and a breaker bar. Make sure you open the filler plug first because if you can't open the filler then you don't want to drain the diff as you will not be able to refill. Also, get new sealer gaskets. My diff was leaking badly when I bought my car, thought I was in for major $s. Turns out the po had used a really bad sealing ring on the drain plug. I happened to have a couple extra gaskets from my Saab 900 (same size as Saab oil plug gasket) and that took care of the leak.

[KenB]

Sorry to hijack...my rear is whining, I changed the oil twice in the last 2 years. My indy used 90w I think, was fine until this fall when I noticed some noise when driving with the windows closed. The last time I bought Royal Purple 75-90w with LSD additive. It didn't improve the noise. Would using the 140 decrease the noise or should I start thinking about looking for a new rear end? Bently doesn't specify weight, just has letter designations...I was told by the dealer to use the 90w.

[zman-95-540i]

Definitely make sure the filler plug can open first. Mine were a major pain to get off. You can get a special Facom tool that fits in there pretty good. Not much room to work with.

[Russell]

Some models require synthetic lube. I know the 95 does, I believe, every 60,000 miles. I think the non-sythethic should be changed every 30,000 miles. My indy used Redline in my 95.

[Russell]

You may need to replace it. I had an e28 that did it for years. I was told the only practical option was to replace with a factory rebuilt or used diff. Typical shops do not generally rebuild.

[philbyil]

As others have said, get the gaskets first and make sure you loosen the fill plug before draining out the axle :D

And, being entirely anal, I replace my tranny fluid (Mobil1 Synthetic ATF), rear axle fluid (Mobil1 75w90) and power steering fluid (Mobil1 Synthetic ATF) along with the brake fluid (Ate Typ200/Super Blue) and engine coolant (Genuine BMW w/Distilled water) every 2 years.