Diff Problems?

[Turnerdv10]

Ive got a Bmw 325sei 1992 auto possible having problems with rear diff.

three garages have looked at this car so far this is what theyve said.

1st garage your rear axle bushes have gone.
2nd garage Nothing wrong with any bush on the back of the car but there is to much play on the rear diff and your front n/s has gone
3rd garage nothing wrong with your rear diff no play what so ever .

The problem im having is like a bump steer coming from the back no noise from the diff what so ever,( i must admit tho it is leaking or has been leaking) when going over very un even roads a very load rattling coming from the back.

Any ideas your help is much appreicated