Checks  | Action  | 
|---|---|
Flat spot on the pinion or the ring gear teeth  | Replace the pinion and the ring gear. Refer to Drive Pinion and Ring Gear Replacement .  | 
Flat spot on the pinion bearing  | Replace the bearing. Refer to Drive Pinion Bearings Replacement .  | 
Worn pinion splines  | Replace the pinion. Refer to Drive Pinion and Ring Gear Replacement .  |