G'Day Team,
Our series 1 VR wagon has a problem reversing up our steep driveway. Something towards the rear of the car is binding as we reverse up the drive but doesn't show itself on flatter ground.

At first we thought it was just the cold Canberra weather binding the rear brakes but further trouble shooting has shown that the problem only exists when reversing up steep slopes. The drive way is about 15m long and the car will bind 3 times on average as it is reversed up. The car shudders but does not stop unles the absolute minimum of power to go up the slope is applied. Other than that, more power only increases the violence of the shuddering.

I suspect the diff but it could be the gearbox (auto). Is there some part that could fall forward to cause the binding? Any ideas?

Thanks
Pat