This oil seal fits in the gearbox housing to retain lubricating oil and exclude contaminants. It sits at the shaft exit point, where the rotating shaft passes through the housing wall. The seal’s lip contacts the shaft surface to prevent oil leakage along the shaft. A worn or hardened seal allows oil to weep from the gearbox, leading to low lubricant levels and potential gear or bearing damage. The original manufacturer’s seal matches the housing bore tolerance and shaft contact surface, so no additional shimming or adapter is required. On installation, ensure the seal lip faces the oil side and that the housing bore is clean and free of burrs.