I have a tc3 car that I race at my local track. I have been experiencing difficultly with the differentials. They either loosen up on me. Or the Screw breaks inside the diff. I really would appreciate any advice you can give me.

Thanks Rick

It maybe time to replace the bolt and nut in that diff. It sounds as though the nut is worn out and that you are trying to get it tight enough that it does not loosen up and break it. Check your manual and see if you are putting the diff in the correct side. That the nut is facing the correct way, in backwards has a tendancy to loosen from the torque when is applied to the diff.
Next time that you have a question fire away, but please put it in the general discussion area not in the track discussion area.