Pinion Flanges

The purpose of the pinion seal, also known as the pinion shaft, is to keep oil in and any water, dirt, or other foreign objects out. The differential will remain in good condition and continue to function as intended as long as the pinion seal is present and functioning properly. Both a little leak where fluid leaks out and a severe leak that might destroy the differential bearings and gears can arise from a failing pinion seal. There won't be much risk of internal damage happening as long as the seal is changed quickly.