My M56 gearbox just gave up. Lost 1st and 2nd, and 3 and reverse are rough and smelly although nicely selectable. As luck would have it, I've been offered an M59 with viscous doodaa.
I was originally saving my pennies for a Gripper Diff. Now my gearbox has packed up, the M59 seems like a good way to fix the more urgent need of having 5 useable gears; AND get some sort of improvement on traction in the corners.
I've never driven an FWD with viscous coupler, are they any good?
Also, can a gripper diff be fitted to an M59 box?