This oil seal fits on the power take-off shaft output housing. It prevents transmission oil from leaking past the shaft where it exits the rear of the tractor. The seal's lip rides on the rotating PTO shaft, keeping lubricant inside the housing while excluding dirt and moisture from entering the bearing cavity. A worn seal allows oil to weep from the housing, which can lead to bearing starvation and eventual shaft damage if left unchecked. Corteco manufactures this seal to match the original housing bore and shaft contact surface, so no shimming or adapter is needed during installation. Replace the seal whenever the PTO shaft or bearing is serviced.