Radiator Fan Viscous
RADIATOR FAN VISCOUSREMOVAL
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.
1. Disconnect negative battery cable from battery.
2. Remove coolant reserve/overflow container from fan shroud and lay aside. Do Not disconnect the hoses or drain coolant from the container.
3. The thermal viscous fan drive/fan blade assembly is attached (threaded) to the water pump hub shaft (Fig. 37). Remove the fan blade/viscous fan drive assembly from the water pump by turning the mounting nut counterclockwise as viewed from the front. Threads on the viscous fan drive are RIGHT HAND. A 36 MM Fan Wrench should be used to prevent pulley from rotating (Fig. 36).
4. Do Not attempt to remove the fan/viscous fan drive assembly from the vehicle at this time.
5. Do Not unbolt the fan blade assembly (Fig. 37) from viscous fan drive at this time.
6. Remove the fan shroud-to-radiator mounting bolts.
7. Pull the lower shroud mounts out of the radiator tank clips.
8. Remove the fan shroud and fan blade/viscous fan drive assembly as a complete unit from vehicle.
9. After removing the fan blade/viscous fan drive assembly, do not place the viscous fan drive in a horizontal position. If stored horizontally, silicone fluid in the viscous fan drive could drain into its bearing assembly and contaminate lubricant.
CAUTION: Do not remove water pump pulley-to-water pump bolts. This pulley is under spring tension.
10. Remove four bolts securing fan blade assembly to viscous fan drive (Fig. 37).
CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. They are marked with the word REVERSE to designate their usage. Installation of the wrong fan or viscous fan drive can result in engine overheating.
CLEANING
Clean the fan blades using a mild soap and water. Do not use an abrasive to clean the blades.
INSPECTION
WARNING: DO NOT ATTEMPT TO BEND OR STRAIGHTEN FAN BLADES IF FAN IS NOT WITHIN SPECIFICATIONS.
CAUTION: If fan blade assembly is replaced because of mechanical damage, water pump and viscous fan drive should also be inspected. These components could have been damaged due to excessive vibration.
1. Remove fan blade assembly from viscous fan drive unit (four bolts).
2. Lay fan on a flat surface with leading edge facing down. With tip of blade touching flat surface, replace fan if clearance between opposite blade and surface is greater than 2.0 mm (0.090 inch). Rocking motion of opposite blades should not exceed 2.0 mm (0.090 inch). Test all blades in this manner.
3. Inspect fan assembly for cracks, bends, loose rivets or broken welds. Replace fan if any damage is found.
INSTALLATION
1. Install fan blade assembly to the viscous fan drive. Tighten the bolts (Fig. 37) to 24 Nm (18 ft. lbs.) torque.
2. Position the fan shroud and the fan blade/viscous fan drive assembly to the vehicle as a complete unit.
3. Install the fan shroud.
4. Install the fan blade/viscous fan drive assembly to the water pump shaft (Fig. 37). Tighten mounting nut to 50 Nm (37 ft. lbs.).
5. Install the coolant reserve/overflow container to the fan shroud.
6. Connect the negative battery cable.
NOTE: Viscous Fan Drive Fluid Pump Out Requirement: After installing a new viscous fan drive, bring the engine speed up to approximately 2000 rpm and hold for approximately two minutes. This will ensure proper fluid distribution within the drive.