You should go to "Harry's You pull It" in either Hazelton, Allentown, and I think maybe in Pittsburg to get a replacment differential for less thatn $100, then replace it. I can overhaul a differential for $360 plus parts, but you can buy a used good one for much less. It is not a complicated operation to change out. Differntial repairs are for the experieinced. Everything in there is totally mechanical, no mysteries. All you need is some basic tools, a feeler gauge, the replacement parts, and a torque wrench.