Genuine OEM Mini Crankshaft Pulley Bolt, part number 11237829918. This specialized bolt is designed to securely fasten the crankshaft pulley to the crankshaft, ensuring proper engine timing and accessory drive operation. The correct torque and thread specification are critical for engine integrity. Genuine OEM bolts are manufactured to precise tolerances to withstand the high stresses and vibrations within the engine. Using the correct fastener is essential for reliable engine performance.