Crankshaft oil seal oe 31537507698 10*15.5*22MM for BMW

The crankshaft oil seal is a key sealing component at the connection point between the engine crankshaft and external parts. Its core function is to prevent engine oil leakage and block external dust and impurities from entering the engine interior.

• Sealing and leak-proofing: This is its most important function. It can closely fit the mating surface between the crankshaft and the cylinder block (or oil pan), preventing the engine oil in the oil pan from leaking to the outside of the engine through the gaps in the rotation of the crankshaft.
• Isolating impurities: While preventing oil leakage, it can also block dust, sand, moisture and other impurities in the air from entering the engine interior, avoiding these impurities from contaminating the oil or wearing out precision components such as the crankshaft.
• Maintain engine oil level: By effectively sealing, ensure that the engine oil level remains stable within the normal range, providing continuous and sufficient lubrication for moving parts such as the crankshaft and connecting rods, and avoiding excessive wear caused by insufficient oil.