Best I recall, there's a short tail shaft that connects the prop shaft to pinion gear inside diff via splines. It's the splines that get lubed. Something thick and gooey I should think. Some have used loctite, not because it may come loose, but because it leaves a gummy residue. Memory's not what it used to be though, YMMV.
Diff Clunk advise
- Thread starter 3point0
- Start date
I had the exact same problem, if you visit Shipkillers website you will see a BMW news bulletin on how to repair the problem:-
http://www.shipkiller.com/SI%20B%2033%2004%2008%20-%20Differential%20input%20flange%20mating%20surface%20with%20the%20input%20drive%20pinion%20is%20insufficiently%20greased%20-%20Aug%202009.pdf
I had my local indy carry out the repair with the grease/seal ordered form BMW.
Came to £170 in total, and no more clunking ever since
http://www.shipkiller.com/SI%20B%2033%2004%2008%20-%20Differential%20input%20flange%20mating%20surface%20with%20the%20input%20drive%20pinion%20is%20insufficiently%20greased%20-%20Aug%202009.pdf
I had my local indy carry out the repair with the grease/seal ordered form BMW.
Came to £170 in total, and no more clunking ever since