Hi all,

The gearbox in my daughter's 2001 Cooper let go this weekend. It had been a little noisy in 4th and 5th, but it finally let go with a huge bang.

I am now just trying to determine what might have gone and would appreciate anyone's input. When trying to move the car backwards and forwards in 1st or reverse gear, there is huge clunk every few feet and both wheels can be seen to move backwards and forwards in the wheel arches.

Sometimes, it will not even take up drive when letting the clutch out.

Does this sound like the diff?

Sounds like you could have lost a few gear teeth or a bearing has disintegrated completely?
Could be anything though if its gone on the move with a bang, and if it was a bearing falling apart that in itself could have caused other damage on its way, the box has got to come out I would think, I doubt its an in situe fix somehow.
Good name by the way.

The crown wheel sometimes spins on its shaft so you loose all drive to the wheels.........I believe some were bonded to the shaft and it can eventually break down.

Lots more info here:
Early MINI Rover Midland Gearbox - Forums (http://forum.minicooper.org/showthread.php?t=9643)

Minigearboxes do recon boxes and fitting at a good price:
mini gearbox, gear fix - Mini recon gearboxes | BMW MINI cheap gearboxes (http://www.minigearboxes.co.uk/)