This seal ring sits inside the wet clutch housing of the tractor transmission. It prevents pressurized oil from leaking past the rotating clutch hub, maintaining the hydraulic pressure needed for clutch-pack engagement and disengagement. The ring is a static-to-dynamic seal; its inner face rides on the hub while the outer face seats in the housing bore. A worn or hardened seal causes a pressure drop that leads to clutch slip or delayed engagement. The manufacturer machines the ring to match the original housing groove geometry, so the seal compresses to the correct interference without requiring shims or adapters. On reinstall, clean the bore and hub surfaces, and verify the seal is seated fully before reassembling the clutch pack.