This is an aftermarket replacement orbital unit, part number AL41631, designed to be compatible with various John Deere tractors, including models like the 1640 and other 20 Series tractors. As a non-OEM alternative, this orbital unit provides a cost-effective solution for maintaining or repairing your agricultural machinery's steering system. The orbital unit, often referred to as a steering unit or hydraulic steering valve, is a crucial component in the hydraulic power steering system of agricultural tractors. It translates the rotational input from the steering wheel into hydraulic flow, directing fluid to the steering cylinders to control the wheels. A properly functioning orbital unit ensures smooth, responsive, and effortless steering, which is essential for maneuverability and operator comfort during long hours in the field. This compatible AL41631 orbital unit is engineered to meet the functional specifications required for seamless integration into your John Deere equipment. It helps restore precise steering control, enhancing operational safety and efficiency. Ideal for farmers and mechanics looking for reliable replacement parts without the OEM price tag, this aftermarket orbital unit offers a dependable solution for hydraulic steering system repairs.