Genuine OEM Citroen Speed Reducer Shaft Pinion, part number 9839382180. This precision-machined gear component is a vital part of the vehicle's transmission or drivetrain assembly. It functions to reduce rotational speed and increase torque, contributing to the smooth and efficient transfer of power. Located within the gearbox, it works in conjunction with other gears to achieve various drive ratios. Using a genuine OEM shaft pinion ensures exact tooth profiles, material hardness, and dimensional accuracy, which are crucial for quiet operation, long service life, and proper engagement within the transmission.