In Reply to: Diagnosis of rear end creak. (anyone agree?) posted by george on June 10, 2001 at 17:57:05:
My father was a Master Tech, and helped me fix it when he was alive. You need to goto a BMW Dealer. BMW contracted with Castrol to make a diff fluid specifically for BMW Diffs. It's call "X-??" something I can't remember the number. You have to request this special diff fluid, otherwise they will put the regular stuff in and that won't work. You can't get that stuff off the shelves. Try the redline and if the noise doesn't go away. Goto the Dealer and ask for the special diff fluid.
Pat '89 M3 - quite rear end :-)