Genuine OEM Volkswagen Adjusting Washer, part number 02M409280AD. This washer is used for precise adjustment within the transmission or differential assembly, typically to set bearing preload or gear mesh. Its exact thickness and material properties are critical for the smooth and reliable operation of the drivetrain. Genuine OEM adjusting washers are manufactured to strict tolerances, ensuring they perform as intended and contribute to the longevity of the transmission or differential.