Whether installing a new ring and pinion or replacing bad rear end bearings, purchasing a rebuild kit to do an installation is highly recommended. In most situations, bearings and seals can be purchased from any parts store, but it is difficult to find the crush sleeve, shims, pinion nut, gasket, and compound that are usually necessary when removing a pinion nut, taking the cover off, or disassembling the differential. We include the highest quality components in our kits–most are available in either Timken or Koyo bearings. We suggest you identify your needs accordingly and choose the appropriate kit that best matches your needs.