At high relative speeds and longer slip phases, the temperature and pressure inside the clutch sharply increase. As a consequence, the transferable torque also rises steeply (Hump effect). Among other things, this steep rise results from the mechanical contact between certain clutch lamellae. As a consequence of the resulting friction, the transferable torque increases many fold over the transferable visco-hydraulic torque. This constructionally influenced torque increase acts a self-protection against over-heating. If the transferable torque is insufficient, the lamellae generally seize. An increased in the heat-input to the clutch overloads the sealing washers.
The figure illustrates the characteristic of torque, pressure and temperature at a constant speed difference.