This oil seal sits at the outboard end of the front-axle final-drive housing. It retains lubricating oil inside the planetary-gear set while excluding dirt and moisture from the wheel-end environment. The seal lip rides on the rotating shaft or hub; any leakage past the lip indicates that the sealing edge has hardened or worn, which can lead to gear or bearing damage from oil loss or contamination. Corteco manufactures this seal to match the original housing bore and shaft diameter, so the interference fit and lip pressure are correct for the application. On installation, inspect the shaft surface for grooves or pitting and lubricate the seal lip before pressing the seal squarely into the bore.