Fan clutches reduce the drain of engine power and improve the efficiency of a vehicle's cooling system. Fan clutches are fluid coupling devices which provide air flow through the radiator by using the water pump shaft to power a fan blade.
Fan clutch replacement may be required when any of the following problems exist:
- Engine Overheating
- Silicon leaking from fan clutch unit
- Fan spins with little or no resistance (free wheels)
- Greasy build up at thermal spring or where shaft exits rear housing
- Fan clutch vibrates on shaft or will not turn
- Squealing noises from bearing
* NOTE:THE FAN CLUTCH SHOULD BE CHECKED FOR POSSIBLE REPLACEMENT WHEN A WATER PUMP IS INSTALLED.
Thermal Fan Clutches
Thermal fan clutches have a built-in thermostat coil spring that detects the air temperature passing through the radiator and air conditioning condenser. The fan clutch engages and provides air flow, only when cooling is needed. When disengaged, the fan clutch "powers down" reducing power drain and increasing fuel economy. When engaged, the fan clutch spins at approximately 75% of the water pump speed. The fan clutches disengage and spin at about 33% of the water pump's speed when cooling is not required.
This results in:
- More efficient use of engine power
- Improved fuel economy
- Less fan noise
- Extended belt and water pump life
Non-Thermal Fan Clutches
Davies, Craig non-thermal fan clutches are constantly engaged and have a limited maximum spin rate. A non-thermal fan clutch achieves proper fan rotation speeds for necessary cooling; however; the constant engagement of the fan clutch decreases engine efficiency in comparison to a thermal fan clutch.
IMPORT/COMPACT FAN CLUTCHES
The slim line design and the use of mounting studs(like OE) instead of bolts makes installation much easier. The lighter weight improves fuel economy and reduces stress on the water pump. As with all Davies, Craig fan clutches, strict attention to quality standards is constantly maintained during manufacturing to provide better performance, easier installation and longer product life.
HOW TO DETECT A FAULTY FAN CLUTCH
- ENGINE OVERHEATING – with engine hot and ignition off, spin fan. I-1/2 revolutions indicates a worn clutch.
- EXCESSIVE FAN CLUTCH PLAY - push the tip of the fan blade in and out. Any visible looseness in the clutch shaft means that the bearing is worn.
- GREASY BUILDUP - Oily streaks 5. radiating outward from the hub shaft or fluid leaking at centre of thermostat spring.
- FREEZING UP - If the fan blade cannot be rotated by hand, or if hand rotation causes a harsh rumbling, the fan clutch bearing has failed.
- SHAFT VIBRATION - The fan clutch is mounted on the water pump between the water pump shaft and the fan. Any vibration can mean a worn bearing in the water pump or fan clutch. Since the fan clutch and water pump have about the same life span, it makes sense to replace both at the same time.
Please visit our buy online section to view the Davies Craig FAN CLUTCHES range.