Genuine OEM BMW Engine Crankshaft Pulley, part number 11237597422. This pulley is mounted on the crankshaft and serves to transfer rotational power to drive various engine accessories such as the alternator, power steering pump, and air conditioning compressor. Its precise balance and material composition are critical for smooth operation and longevity. Genuine OEM pulleys are manufactured to exact specifications to prevent vibration and ensure proper accessory function.