This seal ring fits into the three-point linkage housing to prevent fluid leakage between the shaft and the housing bore. It sits at the interface where the lift-arm shaft passes through the casting, retaining hydraulic oil inside the system. A worn or hardened seal allows oil to weep past the shaft, which reduces lift capacity and can cause visible drips under the tractor. The original part matches the housing's bore tolerance and the shaft's running surface, so no adapter sleeve or shimming is needed. On installation, inspect the shaft contact area for scoring and lubricate the seal lip before pressing it into place.