Genuine OEM BMW Engine Crankshaft Thrust Bearing, part number 11217841617. This component is critical for controlling the axial (end-to-end) movement of the crankshaft within the engine block. By maintaining precise crankshaft end play, it prevents excessive wear on other engine components and ensures smooth operation. Genuine OEM thrust bearings are manufactured with specific bearing materials and precise dimensions to withstand high loads and temperatures, ensuring the longevity and reliability of the engine's rotating assembly.