Variable Speed Cooling Fans: Description

This unit is basically the same as the thermostatically controlled fan clutch except it is not controlled by a temperature sensitive coil. It allows the fan to be driven in normal manner at low speeds while limiting the top speed of the fan to a predetermined level at higher speeds. The silicone in the clutch housing provides a more positive drive at lower speeds and allows greater slippage between the driven member and driving member at higher engine speeds.