GM Genuine Parts Manual Transmission Gear Bearings are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These bearings, one of several, help protect various shafts and gears in your vehicle's drive train against damage caused by heat producing friction that arises between the rotating components. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).