This seal ring is an original AGCO component designed to prevent fluid leakage at the gearbox interface. It sits between the housing and the rotating shaft, maintaining a static seal that keeps lubricating oil contained within the transmission. A worn or hardened seal allows oil to weep past the shaft, leading to low gearbox oil level and potential gear or bearing damage. As an original part, its cross-section and inner diameter match the factory seal groove geometry, so no shimming or adapter is needed for correct compression. On reinstall, ensure the seal face is clean and free of burrs to avoid immediate leakage.