This PTO O-ring seals the connection between the tractor’s power take-off shaft and the driven implement, preventing lubricant leakage at the coupling point. It sits in the groove on the PTO shaft housing, where it compresses against the mating flange to maintain a closed hydraulic or oil-bath circuit. A worn or hardened O-ring allows oil to weep past the seal, which can lead to clutch-slip or bearing starvation on the implement side. The original AGCO part is molded to the same cross-section profile as the factory seal, so it seats fully in the groove without requiring additional sealant. On installation, ensure the groove is clean and free of burrs; lubricate the O-ring lightly with assembly grease to prevent rolling during shaft insertion.