[bl-is-future]

could be a number of things. ex. bearings, bent or warped drive shafts, bad housings for gears to make them crooked. So many variables. The best way is start at the transmission, if it is smooth got to the front or the rear, and so on. OH and shimming is jsut making sure you have a tight mesh with the ring and diff gear. Not so tight it can barely move but tight to where the gear cannot move to creat slop in the mesh thus creating broken or chipped teeth.