Chrysler RAM TRUCK 2500 1994 Service Manual page 299

7 - 44 COOLING SYSTEM
TYPICAL
CONSTANT
T E N S I O N HOSE
CLAMP
TYPICAL
HOSE
CLAMP
NUMBER/LETTER
LOCATION
F A N BLADE
ASSEMBLY
THREADED
NUT
WATER
PUMP
PULLEY PULLEY
BOLTS
WATER PUMP
THREADED SHAFT
(WATER PUMP HUB)
J9407-39
VISCOUS FAN DRIVE
CRANKSHAFT
PULLEY
J9307-32
' Fig. 68 Clamp Number/Letter Location
REMOVAL
(1) Disconnect negative battery cable from battery.
(2) Remove throttle cable at top of fan shroud.
(3) Except 8.0L V-10 Engine: Unsnap coolant re­
serve/overflow tank from fan shroud and lay aside.
The tank is held to shroud with T-shaped slots. Do
not disconnect hose or drain coolant from tank.
(4) The thermal Viscous Fan Drive/Fan Blade As­
sembly is attached (threaded) to water pump hub
shaft (Fig. 69). 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 R I G H T H A N D . A Snap-On 36
M M Fan Wrench (number SP346 from Snap-On
Cummins Diesel Tool Set number 2017DSP) can be
used. Place a bar or screwdriver between water
pump pulley bolts (Fig. 69) to prevent pulley from ro­
tating.
Do not attempt to remove fan/viscous fan drive as­
sembly from vehicle at this time.
Do not unbolt fan blade assembly (Fig. 69) from
viscous fan drive at this time.
(5) Remove four fan shroud-to-radiator mounting
bolts.
(6) Remove fan shroud and fan blade/viscous fan
drive assembly as a complete unit from vehicle.
After removing fan blade/viscous fan drive assem­
bly, do n o t place viscous fan drive i n horizontal po­
sition. I f stored horizontally, silicone fluid i n the
viscous fan drive could drain into its bearing assem­
bly and contaminate lubricant.
Fig. 69 Fan Blade/Viscous Fan Drive—Gas
Engines—Typical
CAUTION: Do not remove water pump pulley-to-wa­
ter pump bolts (Fig. 69). This pulley is under spring
tension.
(7) Remove four bolts securing fan blade assembly
to viscous fan drive (Fig. 69).
INSPECTION
The fan cannot be repaired. I f fan is damaged, i t
must be replaced. Inspect fan as follows:
(1) Remove fan blade and viscous fan drive as an
assembly from the engine. Refer to preceding Re­
moval procedure.
(2) Remove fan blade assembly from viscous fan
drive unit (four bolts).
(3) Lay fan on a flat surface with leading edge fac­
ing down. With tip of blade touching flat surface, re­
place fan i f clearance between opposite blade and
surface is greater than 2.0 mm (.090 inch). Rocking
motion of opposite blades should not exceed 2.0 mm
(.090 inch). Test all blades i n this manner.
WARNING: DO NOT ATTEMPT TO BEND OR
S T R A I G H T E N FAN B L A D E S IF NOT WITHIN S P E C I ­
FICATIONS.
(4) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan i f any damage is
found.