How to Change a Fan Clutch

by Don Bowman

The fan clutch is designed to freewheel when the temperature of a car's engine does not require additional air movement through the radiator. It is also designed to freewheel when the engine is being accelerated. This frees up horsepower and saves fuel at the same time. As the engine temperature rises, the heat is transferred through the shaft of the fan to the clutch. The heat causes the silicone in the fan clutch to expand and locks up the fan to the shaft, increasing the speed of the fan.

Loosen the bolts if the fan clutch being removed is held on by four bolts. Break them loose with the 13mm wrench but do not remove them. The four bolts are located in the fan pulley where it attaches to the water pump. If the fan being removed is the type where it is held on to the water pump pulley by one very large nut, use the fan lockdown to hold the pulley. Spread the arms of the lockdown to fit over two of the bolts in the fan sprocket. Hold the handle while using the large wrench to break the large nut free. It will turn counterclockwise to come off.

Remove the accessory belt if the fan clutch is held on by four bolts. There is no need to remove the accessory belt if the fan clutch is held on by the large nut. The belt does not interfere.

Unscrew the four bolts and the fan. If you have the large nut style on the fan, rotate the fan counterclockwise to remove it.

Lay either one of these fan styles on a bench or flat surface and unscrew the bolts holding the fan clutch to the fan. They are usually four 13mm bolts in the center of the fan. Pull the fan clutch away from the fan.

Match the new fan clutch to the fan, screw the bolts in and tighten. Replace the fan and remaining parts in reverse order of removal.

Items you will need

About the Author

Don Bowman has been writing for various websites and several online magazines since 2008. He has owned an auto service facility since 1982 and has over 45 years of technical experience as a master ASE tech. Bowman has a business degree from Pennsylvania State University and was an officer in the U.S. Army (aircraft maintenance officer, pilot, six Air Medal awards, two tours Vietnam).