Fan Blade: Service and Repair

REMOVAL








Some engines have the mechanical fan/viscous fan drive assembly mounted directly to the water pump hub. It may also be mounted to a hub/bearing attached to an aluminum bracket on the right front side of engine.
1. Loosen but do not remove at this time, the four fan hub mounting nuts.
2. Remove accessory drive belt.
3. Some models with certain engines may require the removal of the fan shroud to remove the viscous fan drive. The fan shroud and fan blade/viscous fan drive should be removed from the vehicle as one assembly.
4. Remove four fan hub mounting nuts and remove fan/viscous fan drive assembly from vehicle.
5. After removing fan blade/viscous fan drive assembly, do not place thermal viscous fan drive in horizontal position. If stored horizontally, silicone fluid in viscous fan drive could drain into its bearing assembly and contaminate lubricant.

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

NOTE: 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.

1. Assemble fan blade to viscous fan drive. Tighten mounting bolts to 24 Nm (18 ft. lbs.) torque.
2. Position mounting flange of fan blade/viscous fan drive assembly onto hub. Install four nuts and tighten to 27 Nm (20 ft. lbs.) torque. Tighten the first two nuts 180 degrees apart. Then tighten last two nuts.

CAUTION: When installing a serpentine accessory drive belt, the belt MUST be routed correctly. If not, the engine may overheat due to the water pump rotating in the wrong direction.

3. Install accessory drive belt.