Well, I brought my car into the local garadge to have a new drivers side tie rod put in. They where looking over other parts of the car and said that I need a new rear differential. The fluid is all black and metalic. What the heck should I do? They said it would be four hours of laber plus the part cost. I think this might be a good time to get some gears if they are going to put in a new differential. How much would this all cost?