Viscous fan drive

REMOVAL

(1) Disconnect battery negative cable.

(2) The thermal viscous fan drive/fan blade assembly is attached (threaded) to water pump hub shaft (Fig. 67). Remove fan blade/viscous fan drive assembly from water pump by turning mounting nut counterclockwise as viewed from front. Threads on viscous fan drive are RIGHT HAND. A Snap-On 36 MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool Set number 2017DSP) and Special Tool 6958 Spanner Wrench with Adapter Pins 8346 can be used to hold the pulley still. (Fig. 66) to prevent pulley from rotating.

(3) Do not attempt to remove fan/viscous fan drive assembly from vehicle at this time.

(4) Do not unbolt fan blade assembly (Fig. 68) from viscous fan drive at this time.

(5) Remove upper fan shroud attaching hardware (Fig. 69).

(6) Remove upper fan shroud and fan blade/viscous fan drive from vehicle.

(7) After removing fan blade/viscous fan drive assembly, do not place viscous fan drive in horizontal position. If stored horizontally, silicone fluid in the viscous fan drive could drain into its bearing assembly and contaminate lubricant.

(8) Remove four bolts securing fan blade assembly to viscous fan drive (Fig. 68).

INSTALLATION

(1) Install fan blade assembly to viscous fan drive.

Tighten bolts (Fig. 68) to 23 N*m (17 ft. lbs.) torque.

(2) Position fan blade/viscous fan drive assembly and upper shroud into vehicle.

Fig. 66 Fan Blade and Viscous Fan Drive Removal

1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER PINS 8346

2 - FAN

Fig. 67 Fan Blade/Viscous Fan Drive-4.7L/5.2L/5.9L Engine

1 - FAN AND VISCOUS DRIVE

2 - WATER PUMP THREADED SHAFT

(3) Install fan shroud retaining screws (Fig. 69).

(4) Install fan blade/viscous fan drive assembly to water pump shaft (Fig. 67).

(5) Connect battery negative cable.

Fig. 68 Viscous Fan Drive and Fan Blade

1 - VISCOUS FAN DRIVE

2 - FAN BLADE

3 - SCREW AND WASHER

Fig. 69 Upper Fan Shroud Removal/Installation

1 - RADIATOR

2 - ELECTRIC COOLING FAN

3 - UPPER SHROUD AND OVERFLOW BOTTLE

4 - SCREW

5 - LOWER SHROUD