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Got an LSD. Now what?


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After convincing myself that I don't really need and LSD, low and behold..a local guy was selling a 3.91 E21 LSD and I lost all my common sense on bought it.  "Saints be Praised" he threw in a couple of E21 rear axles too. 

It has about 150K on it. Sat for 5 years on the shelf.  Worked well on a test rig recently and oil drained very clean.  It is dirty as heck on the outside, but intentionally kept that way to prove there were no leaks. 

Interesting tid bit. It was pulled off a car with an automatic transmission. Did any E21's come with that combo? I thought the LSD's were only on 320iS's 


I am not a mechanic...So now what? 

Is it safe to blast it with the power washer the get the crud off? Should I take it to the local Joe's Differentials and Doughnuts shop to have it checked out or just fill it with Redline and move forward?

For the Axles: Is there a way to tell which side was inboard vs out? Would like to keep the inboard CV's due to less wear and tear. Also do I need a specialty shop to put 02 outer CV's on the axles or could I drop it anywhere? 


Lastly: If I do need a shop. Anyone have any recommendations in the Portland/Salem/Eugene area? 


Thank you for any help. 





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Now, you go do donuts.


a- news to me, but BMW wasn't religious about what got which, and it may have been swapped anyway.

Or ordered that way.


1- no, don't pressure wash.  You can force grit and water under the seals, or into the vent.

A good scrub is fine, though.

2- no, and it doesn't matter.  They are tough as nails, and usually I use one 2002 axle's inners and outers

to convert 2 320 shafts (you want to use the 320 shaft and inner). 

3- you should do the work yourself.  It's easy.  And messy, and satisfying.  I reuse the OE boots- I have had

terrible luck with the aftermarket which, at this point, includes the outfit once known as Mobile Tradition.

4- see 3, you'll be fine.  There are a couple of threads about how, and with solutions to the common problems.


Good score- a 3.91 LSD is a very nice addition to a 5- speed swapped 2002.  And fun even with the 4- speed.




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