Genuine OEM BMW Crankshaft Bearing Shell, part number 11211717528. This bearing shell is a critical component within the engine's crankshaft assembly, designed to reduce friction and wear between the rotating crankshaft and the connecting rods. It is typically made from a specialized alloy to withstand high loads and temperatures. Genuine OEM parts are essential for crankshaft bearings to maintain precise tolerances, ensuring smooth engine operation and preventing premature wear.