Guys,

the GM transmission, I also have one in my X - unfortunately - is per definition not capable to take the power of the X. That is what I was told by a very good BMW mechanic. You find a lot of different stories about dying transmissions here on the board or about rattling noises in different rpm's like I have it. BMW normally tries to have you changing the transmission box which - for my understanding - is an overkill.

Why not have a specialist rebuild it? The clutches in there can be repaired - but it seems not by a BMW dealer.

Good luck, Helmuth