Originally Posted by X5Sport

In my case it was a metal to metal rattle when stationery - broken parts in the TC rattling about. Best described as the sound metal plates make when shaken in a tin. Noises emanated from just behind the engine in the bell housing (exactly where the TC is). Also apparent once the car was warmed up, but not initially apparent on a very cold morning (mine failed on 21/Dec/2009) when it was started to be put on the recovery wagon. It could not be driven up the ramp of the flatbed and had to be winched on.

Also very jerky gearshifts in 1st thru 3rd (4th to 6th were fine) and tended to lock in third when slowing down meaning very hard braking required to hold the car stopped at traffic lights etc. Diesels having so much torque low down meant it just wanted to take off from a halt!! Not fun on icy roads!! 'Sport' mode was non-functional - or at least was ignored by the control system as was 'Manual mode''.

BMW Garage reported the transmission oil as brown/black and smelling burnt (caused by multiple clutches failing due to lack of gearbox hydraulic control pressure).