What is a viscous fan clutch?
What is a viscous fan clutch?
Viscous fan clutches are belt-driven and found on many older rear-wheel-drive passenger cars. They contain a drive and driven plate with annular grooves that fill with a thick viscous silicon fluid. These fans are needed at slow speeds, typically below 35 mph and at idle.
Can a viscous clutch fail?
The key to fan clutch function is its heavy silicone oil, whose viscous properties allow for soft engagement to drive the fan. If it leaks out, the clutch will weaken and eventually fail. Check fan speed. You should be able to audibly detect when the fan clutch engages, with an accompanying rush of air.
How do you test a viscous hub?
When your motor is hot, you should be able to hear the fan kick in. If you can’t, pop the bonnet, and turn the vehicle off while watching the fan. If it comes to a fairly abrupt stop, the fan hub is working properly. If it keeps spinning round and round, your fan hub is knackered and needs to be repaired or replaced.
How do you check a viscous fan clutch?
To confirm the diagnosis, start with this simple test: Spin the fan as hard as you can on an engine that has not been started that day. If the fan rotates more than five times, you can bet the clutch is bad. You should feel some resistance and the fan may spin up to three times, depending on the ambient temperature.
How do you diagnose a bad viscous fan?
Will a bad fan clutch cause AC problems?
Registered. Yes, a bad fan clutch will cause A/C issues. The condenser needs air flow to cool hot refrigerant.
When did the Volvo S60 get the Haldex clutch?
This is why Volvo first reduced the pre-tensioning in 2000 and then replaced the viscous coupling with Haldex clutch on their all wheel drive vehicles in model year 2003 (Volvo s60 has Haldex since 2002). [1] In this case, all wheels are powered at all times.
What is a viscous coupling on a car?
When driving wheels slip, viscous coupling locks and torque is transferred to the other axle. This is an automatic all wheel drive system. The disadvantage of a viscous coupling is that it engages too slowly and allows for excessive wheelspin before transferring torque to another wheels.
Does Volvo use Haldex Traction?
Volvo has used Haldex Traction’s AWD system for nearly all of their models since the introduction of their FWD/AWD platform. However, before the switchover to the Haldex system in 2003, Volvo used a viscous coupling designed by GKN Driveline to transfer torque to the rear axles.
What is the operation of the clutch pack?
Operation of the clutch pack is almost entirely mechanical—a mechanically driven pump and a mechanical linear throttle valve were used to determine wheel slip and lock up of the clutch pack, converting the system from 90% / 10% front/rear torque distribution to 50% / 50% torque distribution within 90 degrees of wheel slip.
