Traxxas 5211R Roller Clutch (One Way Bearing), TRX 2.5, 2.5R, 3.3 Roller clutch (also called one-way bearing) 6 x 8 x 0.5 TW Fits TRX 2.5, 2.5R, 3.3 Remove and clean the bearing after every half gallon. Lubricate with 5w-30 Use a teflon washer between the bearing and backplate