What Does Fan Clutches Mean?

Not known Details About Fan Clutches

Engine fan with viscous drive A fan clutch is a thermostatic engine cooling fan that can freewheel at low temperature levels when cooling is not needed, enabling the engine to warm up much faster, alleviating unnecessary load on the engine. As temperatures increase, the clutch engages so that the fan is driven by engine power and moves air to cool the engine.


This saves power, considering that the engine does not have to totally drive the fan. Nevertheless, if engine temperature level rises above the clutch's engagement temperature setting, the fan ends up being totally engaged, therefore drawing a greater volume of ambient air through the lorry's radiator, which in turn serves to maintain or reduce the engine coolant temperature to an acceptable level.


This is easier to achieve because the engine is mounted longitudinally, with the belt accessory parts installed dealing with the radiator. The fan is mounted on the crankshaft pulley-block or one of the accessory wheels (e. g. the water pump pulley-block) and will spin in between the radiator and the engine, drawing air back through the radiator and blowing it over the engine.


On the other hand, in a front-wheel drive vehicle, the engine is typically installed laterally, with the crankshaft and generally all the significant accessory shafts parallel to the front axle, so regarding straight drive the transaxle; a fan mechanically mounted on an accessory sheave would blow sideways and would not face the radiator.


The conversion of mechanical energy to electricity and back to mechanical rotary power with a fan motor is less effective than a direct mechanical connection, however this is more than compensated by greater control of an electric fan through electronic thermostatic controls which can turn the fan completely off when the engine temperature level is below the setpoint.

Get This Report about Fan Clutches

Some clutches are digitally controlled (rather of bi-metallic strip). These supply the possible to control the level of engagement depending upon any variety of inputs. Common managing elements might consist of engine oil temperature, transmission oil temperature, coolant temperature, Air Conditioning system pressures and ambient air temperature.




When you believe of an automotive cooling system, the first thing that likely comes to mind is your radiatoror possibly your cooling fan. The oft-overlooked doesn't get a lots of credit or attention, however it's an important piece of the cooling formula in numerous lorries. It helps your cooling system operate successfully and your engine operate effectively.


A fan clutch is a temperature-controlled coupling in between the water pump shaft and the fan which enables the fan to be operational at low speeds and detached at greater speeds. This enables the engine to operate more efficiently by eliminating the load that the fan locations on it. So how does it work? It truly depends on the design of fan clutch you select.




Non-thermal clutches run exclusively based on the shaft speed of the water pump. At low and idling speeds, the clutch allows the fan blade to turn at almost a 1:1 ratio. this At high speeds, the silicone fluid within in the clutch will lose its ability to move the energy from the shaft to the fan clutch body (and therefore, the fan) and the fan is then allowed to nearly free-wheel, removing its load from the engine.


However, non-thermal clutches are a lower-cost option than thermal-style clutches. The thermal fan clutch operates in reaction to underhood temperatures. As hot air blows across the radiator, it heats up a thermal spring installed at the front of the clutch. As the spring is heated up, it turns and allows valve ports to open within the clutch.

Fan Clutches for Dummies

This engages the clutch and drives the fan. Once the engine is cooled visit here off, the thermal spring rotates back and closes the valve ports, disengaging the fan. The speed at which a thermal fan clutch spins a fan depends mostly on the precise fan you select. On the Summit Racing website, for example, you'll find 3 different kinds of thermal fan clutches from Hayden alone: This style turns the fan at 60-70 percent of the water pump shaft speed when engaged, and 20-30 percent when disengaged.


This fan style turns the fan at 70-90 percent of the shaft speed when engaged for increased cooling. When disengaged, it turns the fan at 25-35 percent. It's used with deeper-pitch fans (2 1/2 of pitch), and works well with higher operating rpm. Severe task thermal fans turn the fan at 80-90 percent of the shaft speed when engaged and 20-30 percent when disengaged.


This style of fan clutch runs like a thermal clutch, however the ECM/PCM signal manages the level of engagement of the EV clutch. fan clutches. This engagement process is ultimately controlled through the ECM/PCM by the following input variables: Coolant Temperature, Consumption Manifold Temperature, Transmission Oil Temperature, A/C Pressure and Engine Oil Temperature Level.


Like all parts, fan clutches will wear and go to this site need replaced. According to Hayden, here are some signs your fan clutch might need changed: Fan spins exceedingly when engine is stopped (three or more times when hot engine is shut off). Poor A/C performance at idle or low car speeds.


Fan speed does not increase up until engine is excessively hot. Fan blade idea moves more than 1/4-inch front to back (fan clutches). Fan turns roughly or does not turn at all. Excessive fan sound at all speeds due to failed bearing. Vibration that increases with engine speed. Dripping fluid or oily build up around the bearing or thermal spring.

The Only Guide to Fan Clutches

The Fan Clutch is a fundamental part of your cooling system. Its drive shaft connects to the water pump. Then, the fan connects to the clutch housing. The fan clutch's task is to manage when the fan begins and off. It provides airflow when required. It also decreases drag on the engine when not required - fan clutches.