Radiator - Fan - Viscous: Description
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
If the viscous fan drive is replaced because of mechanical damage, the cooling fan blades should also be inspected. Inspect for fatigue cracks, loose blades, or loose rivets that could have resulted from excessive vibration. Replace fan blade assembly if any of these conditions are found. Also inspect water pump bearing and shaft assembly for any related damage due to a viscous fan drive malfunction.
The thermal viscous fan drive is a silicone-fluid-filled coupling used to connect the fan blades to the water pump shaft. The coupling allows the fan to be driven in a normal manner. This is done at low engine speeds while limiting the top speed of the fan to a predetermined maximum level at higher engine speeds. See Fig 1.
On the 3.7L engine, an electric fan is standard and the viscous fan is added on for trailer tow packages only.
On the 2.8L diesel engine, the viscous is standard.
| 1 - VISCOUS FAN DRIVE |
| 2 - THERMOSTATIC SPRING |
| 3 - MOUNTING NUT TO WATER PUMP HUB |