This clutch disc transmits torque from the engine flywheel to the gearbox input shaft. It sits between the pressure plate and the flywheel; the friction facings on both sides grip the flywheel and pressure plate surfaces when the clutch is engaged. The disc hub carries splines that mate with the gearbox input shaft, and the facings are riveted to a cushioned center that absorbs engagement shock. A worn disc causes clutch slip under load, difficulty engaging gears, or chatter during take-up. The manufacturer machines the hub splines and facing thickness to match the original assembly geometry, so no shimming or adapter is required during installation. On reinstall, inspect the pressure plate and release bearing for wear, and torque the pressure-plate bolts in a cross pattern to the specified value.