Driveline

Slipping or chatter are most noticeable when the engine is under load, as when the vehicle is travelling at low speed in a high gear, when driving up a hill, when accelerating to overtake another vehicle, or when towing a trailer.
Slippage increases friction and produces heat which leads to hot spots on the pressure plate. The hotter the clutch gets, the less able it is to maintain its grip, and the more it slips. The vicious cycle that results can burn the clutch facings and damage the flywheel and pressure plate.