This clutch friction disc transmits torque from the engine flywheel to the gearbox input shaft. It is the primary wear element in the clutch pack; the friction material on both faces engages against the pressure plate and the flywheel to transfer drive. As the friction lining wears, the disc thickness decreases, which reduces clamp load and leads to clutch slip under load. The disc is manufactured to the original thickness specification so that the release bearing travel and pedal feel match the factory setup. When installing, ensure the disc is centered in the splined hub before torquing the pressure plate bolts.