This seal ring fits in the gearbox and PTO housing of the host tractor. It prevents oil leakage between the rotating shaft and the stationary housing, maintaining lubricant pressure inside the transmission. A worn or hardened seal ring allows oil to weep past the shaft, leading to low lubricant levels and potential gear or bearing damage. The manufacturer produces this component to the original housing geometry, so the seal seats correctly in its groove without modification. On reinstall, clean the bore and shaft surface, and apply a light lubricant to the seal lip before assembly.