Other than a crack, what would necessitate the replacement of a rear differential center case? The repair was done by the dealership before I purchased the truck and I am doing a little detective work to assemble a complete history of the drivetrain failures on my truck. It it was cracked, what would cause a failure like that? I finaly got the tranny rebuilt and the truck drives like a dream, a whole new truck, but the repair history troubles me, which means I am fully planning on selling the truck the day my extended warranty expires. According to the dealership the differential was fine so I must imagine the problem was caught early, but just replacing the case seems strange to me. Any ideas?

 

Usually, assuming you rule out manufacte defects, Just about the only thing that could crack the case would be racing the truck with slicks or if its a 4x4 running good size tires and gettin into some trouble off-road. I have seen on full size trucks where the preload adjusters would wear into the case, and I have also seen where the rear speed sensor would come apart inside the diff and rather than trying to clean all the pieces of copper wire out, they just replaced the carrier.