This oil seal fits into the crankcase opening to retain lubricating oil and exclude dirt and moisture from the rotating shaft interface. It sits at the point where the crankshaft or a related shaft exits the crankcase housing, forming a dynamic seal that maintains internal crankcase pressure and prevents oil leakage onto the engine exterior. A worn or hardened seal lip allows oil seepage and can draw in abrasive particles, accelerating bearing and shaft wear. This component is manufactured to match the original seal geometry, so the lip contacts the shaft at the correct interference and the outer diameter seats fully in the housing bore without additional shimming. On installation, ensure the seal lip faces the oil side and the shaft surface is free of burrs or scoring.