Viscous Fan Drive - Service Procedures

NO: 07-09-98

GROUP: Cooling

DATE: Dec. 18, 1998

SUBJECT:
Viscous Fan
Drive Service

MODELS:

1998 - 1999 (AB) Ram Van
1998 - 1999 (AN) Dakota
1998 - 1999 (BR/BE) Ram Truck
1998 (ZJ) Grand Cherokee
1998 (ZG) Grand Cherokee (International Market)

NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 3.9L, 5.2L, OR 5.9L GASOLINE ENGINE BUILT AFTER JANUARY 5, 1998 (MDH 0105XX).

DISCUSSION:

Vehicles built after January 5, 1998 have the water pump pulley pressed onto the water pump hub shaft. As in previous models, the viscous fan drive is threaded onto the water pump hub shaft. Because the pulley is pressed onto the hub shaft, viscous fan drive removal/installation procedures are unique.





The fan/viscous fan drive assembly can be removed or installed from the water pump by turning the mounting nut. To remove the fan/viscous fan drive assembly, turn the nut counterclockwise as viewed from the front. To install the fan/viscous fan drive assembly, turn the nut clockwise as viewed from the front. Threads on the viscous fan drive are RIGHT-HANDED. Snap-On 36 mm Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool Set number 2017DSP) can be used to remove/install the fan drive assembly on gasoline engines. To hold the water pump pulley from rotating, place Miller Special Tool 6958 Spanner Wrench onto the water pump pulley with adapter pins 8346 inserted into the holes on the pulley (Figure 1).

NOTE:
REPLACEMENT WATER PUMP P/N 53021018 HAS BEEN SUPERSEDED TO P/N 53021018AB WHICH WILL HAVE THE PULLEY PRESSED ONTO THE WATER PUMP HUB SHAFT. WATER PUMP P/N 53021018 WAS USED TO SERVICE 1993 - 1998 3.9L/5.2L/5.9L (GASOLINE ENGINES) WATER PUMPS.