:(Seems as tho the pinion bearings on my Samurai decided to become real lose. So bad the seal gave up and the gear oil is leaking out. Guess I should have paid closer attention. Anyway I would like some advise on replacing the bearings and seal. What should I expect to pay to have it done at a shop? (socal area) Can a regular shop do a decent job on a Samurai differential? What should a used differential cost? Only one I found online was $400 plus $200 shipping from the midwest.    What would cause the bearings to go out. 80K on the Sami and about half are tow miles. Using Mobil 1 75-90 gear oil. Anyone recommend a shop in either the Antelope Valley (Where it's currently parked) or Orange county area?

Same thing happened to me..... and my wheel bearings went out too. check out my thread it has a good amount of insight. http://www.zukiworld.com/forum/technical-discussion-beginner-repair/rear-axle-bearings-sami/

I am just rebuilding my entire rear axle to save anymore breaks of old parts. I am going with this http://www.lowrangeoffroad.com/index.php/suzuki-samurai-sidekick-differential-master-rebuild-install-kits.html
 
low range off road makes very great quality parts. Its a fairly in depth project from what i can tell.

  Anyone have any info.......

Most shops that can do gearing should be able to rebuild your rear diff without an issue.  If you order the rebuild kit from Low Range Off Road it includes a book that gives the specs for setting the gears back up.

Once nice thing about the SJ series is you can pull your rear axles and just bring in the third member.  That way they don't have to charge you for pulling the diff out.