tow DODGE RAM 2001 Service Owner's Guide

(9) Remove release lever and release bearing from
clutch housing. Apply Moparthigh temperature
bearing grease to bore of release bearing, release
lever contact surfaces and release lever pivot stud
(Fig. 11).
(10) Apply light coat of Moparthigh temperature
bearing grease to splines of transmission input shaft
(or drive gear) and to release bearing slide surface of
the transmission front bearing retainer (Fig. 12). Do
not over lubricate shaft splines. This can result in
grease contamination of disc.(11) Install release lever and bearing in clutch
housing. Be sure spring clips that retain fork on
pivot ball and release bearing on fork are properly
installed (Fig. 13). Also verify that the release lever
is installed properly. When the release lever is
installed correctly, the lever part number will be
toward the bottom of the transmission and right side
up. There is also a stamped ªIº in the lever which
goes to the pivot ball side of the transmission.
(12)
Install transmission. Refer to Group 21, Trans-
mission and Transfer Case, for proper procedures.
(13) Check fluid level in clutch master cylinder.
Fig. 11 Clutch Release Component Lubrication
Points
1 - CLUTCH HOUSING
2 - COAT RELEASE FORK PIVOT BALL STUD WITH HIGH TEMP.
GREASE
3 - RELEASE FORK
4 - APPLY LIGHT COAT HIGH TEMP. GREASE TO RELEASE
BEARING BORE
5 - LUBE POINTS (HIGH TEMP. GREASE)
Fig. 12 Input Shaft Lubrication Points
1 - INPUT SHAFT
2 - BEARING RETAINER
3 - APPLY LIGHT COAT OF HIÐTEMP GREASE TO THESE
SURFACES BEFORE INSTALLATION
Fig. 13 Release Fork And Bearing Spring Clip
Position
1 - FORK
2 - SPRING CLIP
3 - BEARING
4 - SPRING CLIP
6 - 10 CLUTCHBR/BE
CLUTCH DISC (Continued)

On gas engines, the acceptable maximum TIR for
housing bore runout is 0.010 inch. If measured TIR is
more than 0.010 in. (as in the example), bore runout
will have to be corrected with offset dowels. Offset
dowels are available in 0.007, 0.014 and 0.021 in.
sizes for this purpose (Fig. 16). Refer to Correcting
Housing Bore Runout for dowel installation.
On diesel engines, the acceptable maximum TIR
for housing bore runout is 0.015 inch. However,
unlike gas engines, offset dowels are not available to
correct runout on diesel engines.If bore runout
exceeds the stated maximum on a diesel engine,
it may be necessary to replace either the clutch
housing, or transmission adapter plate.
Correcting Clutch Housing Bore Runout - Engine Only
On gas engine vehicles, clutch housing bore runout
can be corrected with offset dowels.
The dial indicator reads positive when the plunger
moves inward (toward indicator) and negative when
it moves outward (away from indicator). As a result,
the lowest or most negative reading determines the
direction of housing bore offset (runout).
In the sample readings shown (Fig. 17) and in Step
7 above, the bore is offset toward the 0.010 inch
reading. To correct this, remove the housing and orig-
inal dowels. Then install the new offset dowels in the
direction needed to center the bore with the crank-
shaft centerline.
In the example, TIR was 0.012 inch. The dowels
needed for correction would have an offset of 0.007
in. (Fig. 17).
Install the dowels with the slotted side facing out
so they can be turned with a screwdriver. Then
install the housing, remount the dial indicator and
check bore runout again. Rotate the dowels until the
TIR is less than 0.010 in. if necessary.If a TIR of 0.053 in., or greater is encountered, it
will be necessary to replace the clutch housing.
Measuring Clutch Housing Face Runout
(1) Reposition the dial indicator plunger on the
housing face (Fig. 18). Place the indicator plunger at
the rim of the housing bore as shown.
(2) Rotate the crankshaft until the indicator
plunger is at the 10 O'clock position on the bore.
Then zero the dial indicator.
(3) Measure and record face runout at four points
90É apart around the housing face (Fig. 19) . Perform
the measurement at least twice for accuracy.
Fig. 16 Housing Bore Measurement Points And
Sample Readings
1 - CLUTCH HOUSING BORE CIRCLE
Fig. 17 Housing Bore Alignment Dowel Selection
1 - SLOT SHOWS DIRECTION OF OFFSET
2 - OFFSET DOWEL
TIR VALUE OFFSET DOWEL
REQUIRED
0.011 - 0.021 inch 0.007 inch
0.022 - 0.035 inch 0.014 inch
0.036 - 0.052 inch 0.021 inch
Fig. 18 Measuring Clutch Housing Face Runout
1 - INDICATOR PLUNGER
2 - DIAL INDICATOR
3 - CLUTCH HOUSING FACE
4 - INDICATOR MOUNTING STUD OR ROD
6 - 12 CLUTCHBR/BE
CLUTCH HOUSING (Continued)

REMOVAL
(1) Remove transmission and transfer case, if
equipped. Refer to Group 21, Transmission and
Transfer Case, for proper procedures.
(2) Remove clutch housing, for NV4500 equipped
vehicles.
(3) Disconnect release bearing from release fork
and remove bearing (Fig. 25).
INSTALLATION
(1) Inspect bearing slide surface on transmission
front bearing retainer. Replace retainer if slide sur-
face is scored, worn, or cracked.(2) Inspect release lever and pivot stud. Be sure
stud is secure and in good condition. Be sure fork is
not distorted or worn. Replace fork spring clips if
bent or damaged.
(3) Lubricate input shaft splines, bearing retainer
slide surface, lever pivot ball stud, and release lever
pivot surface with Moparthigh temperature bearing
grease.
(4) Install release fork and release bearing (Fig.
26). Be sure fork and bearing are properly secured by
spring clips. Also be sure that the release fork is
installed properly. The rear side of the release lever
has one end with a raised area. This raised area goes
toward the slave cylinder side of the transmission.
(5) Install clutch housing, if removed.
(6) Install transmission and transfer case, if
equipped. Refer to Group 21, Transmission and
Transfer Case, for proper procedures.
PRESSURE PLATE
DESCRIPTION
The clutch pressure plate assembly is a diaphragm
type with a one-piece spring and multiple release fin-
gers. The pressure plate release fingers are preset
during manufacture and are not adjustable. The
assembly also contains the cover, pressure plate, and
fulcrum components.
Various sizes and designs of clutch covers are used
for the different engine and transmission combina-
tions. The currently used clutch covers and applica-
tions are listed below.
Fig. 24 Clutch Release Bearing
1 - RELEASE BEARING
2 - RELEASE FORK
Fig. 25 Clutch Release Components
1 - CONED WASHER
2 - CLUTCH HOUSING
3 - RELEASE FORK
4 - RELEASE BEARING AND SLEEVE
5 - PIVOT 23 N´m (200 IN. LBS.)
6 - SPRING
Fig. 26 Clutch Release Fork And
1 - PIVOT BALL
2 - FORK
3 - SLAVE CYLINDER OPENING
4 - BEARING
BR/BECLUTCH 6 - 15
CLUTCH RELEASE BEARING (Continued)

OPERATION
The pilot bearing supports the transmission input
shaft, maintains proper clutch assembly alignment
and allows the transmission input shaft to rotate at a
different speed (RPM) than the engine mounted
crankshaft.
When the clutch pedal is depressed (with vehicle in
drive mode) the clutch disc slows and stops therefore,
the transmission input shaft slows and stops as well.
The pilot bearing allows the engine crankshaft to
continue to rotate even though the transmission
input shaft is stationary.
REMOVAL
(1) Remove transmission, transfer case, if
equipped, and clutch housing. Refer to Group 21,
Transmission and Transfer Case, for proper proce-
dures.
(2) Remove clutch cover and disc.
(3) Using a suitable blind hole puller, remove pilot
bearing.
INSTALLATION
(1) Clean bearing bore with solvent and wipe dry
with shop towel.
(2) Install new bearing with clutch alignment tool
(Fig. 30). Keep bearing straight during installation.
Do not allow bearing to become cocked. Tap bearing
into place until flush with edge of bearing bore. Do
not recess bearing.
(3) Install clutch cover and disc.
(4) Install clutch housing, transmission and trans-
fer case, if equipped. Refer to Group 21, Transmis-
sion and Transfer Case, for proper procedures.
CLUTCH PEDAL
REMOVAL
(1) Remove retaining clips that secure the brake
and clutch pedals to the push rods (Fig. 31).
(2) Remove the brake and clutch master cylinder
pushrods from the pedals.
(3) Remove knee bolster (Fig. 32) for access to
pedal pivot shaft.
(4) Remove brake lamp switch.
(5) Remove retainer from passenger side of pedal
pivot shaft (Fig. 33).
(6) Push pedal pivot shaft toward driver side of
support only enough to remove clutch pedal. It is not
necessary to remove shaft from pedal support
entirely.
(7) Remove clutch pedal.
Fig. 30 Typical Method Of Installing Pilot Bearing
1 - PILOT BEARING
2 - ALIGNMENT TOOL
3 - LETTER SIDE MUST FACE TRANSMISSION
Fig. 31 Clutch Cylinder Push Rod Attachment
1 - PIN
2 - CLUTCH INTERLOCK WIRE
3 - PUSH ROD
4 - CLIP
6 - 18 CLUTCHBR/BE
PILOT BEARING (Continued)

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION............................1
OPERATION.............................2
DIAGNOSIS AND TESTING..................4
PRELIMINARY CHECKS...................4
ON-BOARD DIAGNOSTICS (OBD)...........4
COOLING SYSTEM LEAKS................5
COOLING SYSTEM GAS ENGINE...........7
COOLING SYSTEM DIESEL ENGINE........12
STANDARD PROCEDURE..................15
DRAINING COOLING SYSTEM - 3.9L/5.2L/
5.9L/8.0L ENGINES......................15
DRAINING COOLING SYSTEM - 5.9L
DIESEL ENGINE........................15REFILLING COOLING SYSTEM - 3.9L/5.2L/
5.9L/8.0L ENGINES......................15
REFILLING COOLING SYSTEM - 5.9L
DIESEL ENGINE........................15
ADDING ADDITIONAL COOLANT...........16
COOLANT LEVEL CHECK................16
COOLING SYSTEM CLEANING/REVERSE
FLUSHING............................16
COOLANT SELECTION-ADDITIVES.........17
SPECIFICATIONS........................17
SPECIAL TOOLS.........................18
ACCESSORY DRIVE......................19
ENGINE................................39
TRANSMISSION.........................79
COOLING
DESCRIPTIONÐCOOLING SYSTEM FLOW -
3.9L/5.2L/5.9L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity forvehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
DESCRIPTIONÐCOOLING SYSTEM FLOW -
5.9L DIESEL
The diesel engine cooling system consists of (Fig.
2):
²Cross-flow radiator
²Belt driven water pump
²Belt driven mechanical cooling fan
²Thermal viscous fan drive
²Fan shroud
²Radiator pressure cap
²Vertically mounted thermostat
²Coolant reserve/recovery system
²Transmission oil cooler
²Coolant
BR/BECOOLING 7 - 1

OPERATIONÐCOOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.²Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
AIR CONDITIONING; ADD-ON OR AFTER MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, (Refer to 7 - COOLING - DIAGNOSIS AND
TESTING)
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The powertrain control module (PCM) has been
programmed to monitor certain cooling system com-
ponents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the relay circuit controlling the electric radiator fan,
a Diagnostic Trouble Code (DTC) can be set.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the PCM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
7 - 4 COOLINGBR/BE
COOLING (Continued)

DIAGNOSIS AND TESTING - COOLING SYSTEM
GAS ENGINE
COOLING SYSTEM DIAGNOSISÐGASOLINE ENGINE
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE
GAUGE READS LOW1. Has a Diagnostic Trouble Code (DTC)
been set indicating a stuck open
thermostat?1. (Refer to 25 - EMISSIONS CONTROL -
DESCRIPTION) for On-Board Diagnostics
and DTC information. Replace thermostat
if necessary.
2. Is the temperature sending unit
connected?2. Check the temperature sensor
connector. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - SCHEMATIC -
ELECTRICAL) Repair connector if
necessary.
3. Is the temperature gauge operating
OK?3. Check gauge operation. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER/
ENGINE TEMPERATURE GAUGE -
DESCRIPTION) . Repair as necessary.
4. Coolant level low in cold ambient
temperatures accompanied with poor
heater performance.4. Check coolant level in the coolant
reserve/overflow tank and the radiator.
Inspect system for leaks. Repair leaks as
necessary. Refer to the Coolant section of
the manual text for WARNINGS and
CAUTIONS associated with removing the
radiator cap.
5. Improper operation of internal heater
doors or heater controls.5. Inspect heater and repair as necessary.
(Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND
TESTING) for procedures.
TEMPERATURE
GAUGE READS HIGH
OR THE COOLANT
WARNING LAMP
ILLUMINATES.
COOLANT MAY OR
MAY NOT BE LOST OR
LEAKING FROM THE
COOLING SYSTEM1. Trailer is being towed, a steep hill is
being climbed, vehicle is operated in slow
moving traffic, or engine is being idled
with very high ambient (outside)
temperatures and the air conditioning is
on. Higher altitudes could aggravate
these conditions.1. This may be a temporary condition and
repair is not necessary. Turn off the air
conditioning and attempt to drive the
vehicle without any of the previous
conditions. Observe the temperature
gauge. The gauge should return to the
normal range. If the gauge does not
return to the normal range, determine the
cause for overheating and repair. Refer to
Possible Causes (2-20).
2. Is the temperature gauge reading
correctly?2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER -
SCHEMATIC - ELECTRICAL) . Repair as
necessary.
3. Is the temperature warning illuminating
unnecessarily?3. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - SCHEMATIC -
ELECTRICAL).
4. Coolant low in coolant reserve/overflow
tank and radiator?4. Check for coolant leaks and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
BR/BECOOLING 7 - 7
COOLING (Continued)

(4) Install fan blade/viscous fan drive assembly to
water pump shaft (Fig. 6).
(5) Except 8.0L V-10 Engine: Install coolant
reserve/overflow tank to fan shroud. Snaps into posi-
tion.
(6) Install throttle cable to fan shroud.
(7) Connect negative battery cable.
NOTE: Viscous Fan Drive Fluid Pump Out Require-
ment: 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.
RADIATOR FAN - 5.9L DIESEL
REMOVAL
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 the battery negative cables.
(2) Remove the fan shroud mounting bolts. Posi-
tion fan shroud towards engine.
CAUTION: Do not remove the fan pulley bolts. This
pulley is under spring tension.
(3) The thermal viscous fan drive/fan blade assem-
bly is attached (threaded) to the fan hub shaft (Fig.
7). Remove the fan blade/fan drive assembly from fan
pulley by turning the mounting nut clockwise (as
viewed from front). Threads on the viscous fan drive
areLEFT-HAND.A Snap-On 36 MM Fan Wrench
(number SP346 from Snap-On Cummins Diesel Tool
Set number 2017DSP) can be used. Place a bar or
screwdriver between the fan pulley bolts to prevent
pulley from rotating.
(4) Remove the fan shroud and the fan blade/vis-
cous drive as an assembly from vehicle.
(5) Remove fan blade-to-viscous fan drive mount-
ing bolts.
(6) Inspect the fan for cracks, loose rivets, loose or
bent fan blades.
CAUTION: Some engines equipped with serpentine
drive belts have reverse rotating fans and viscous
fan drives. They are marked with the wordREVERSE 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 fac-
ing down. With tip of blade touching flat surface,
replace fan if 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 in this manner.
Fig. 7 Fan Blade/Viscous Fan Drive
1 - THREADED SHAFT
2 - BOLT (4)
3 - FAN BLADE
4 - THREADED NUT
5 - VISCOUS FAN DRIVE
7 - 44 ENGINEBR/BE
RADIATOR FAN - 3.9L/5.2L/5.9L/8.0L (Continued)

(4) Position thermostat housing to intake manifold.
Note the word FRONT stamped on housing (Fig. 20).
For adequate clearance, thismustbe placed towards
front of vehicle. The housing is slightly angled for-
ward after installation to intake manifold.
(5) Install two housing-to-intake manifold bolts.
Tighten bolts to 23 N´m (200 in. lbs.) torque.
(6) Install radiator upper hose to thermostat hous-
ing.
CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
engine may overheat due to water pump rotating in
wrong direction. Refer to (Fig. 21) for correct 3.9L,
5.2L and 5.9L engine belt routing. The correct belt
with correct length must be used.
(7) Air Conditioned vehicles; Install generator.
Tighten bolts to 41 N´m (30 ft. lbs.).
(8) Install support bracket (generator mounting
bracket-to-intake manifold) (Fig. 16). Tighten bolts to
54 N´m (40 ft. lbs.) torque.
(9) Install accessory drive belt (Fig. 17)(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(10) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Connect battery negative cable.(12) Start and warm the engine. Check for leaks.
Fig. 19 ThermostatÐ3.9L and 5.9L Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVEFig. 20 Thermostat PositionÐ5.2L and 5.9L Engines
Fig. 21 Belt RoutingÐ5.2L and 5.9L Engines
1 - IDLER PULLEY
2 - GENERATOR PULLEY
3 - A/C COMPRESSOR PULLEY
4 - IF W/OUT A/C
5 - POWER STEERING PUMP PULLEY
6 - WATER PUMP PULLEY
7 - CRANKSHAFT PULLEY
8 - AUTOMATIC TENSIONER
BR/BEENGINE 7 - 51
ENGINE COOLANT THERMOSTAT - 3.9L/5.2L/5.9L (Continued)

FAN DRIVE VISCOUS CLUTCH
- 3.9L/5.2L/5.9L/8.0L
DESCRIPTION
The thermal viscous fan drive (Fig. 28) is a sili-
cone-fluid- filled coupling used to connect the fan
blades to the water pump shaft. The coupling allows
the fan to be driven in a normal manner. This is
done at low engine speeds while limiting the top
speed of the fan to a predetermined maximum level
at higher engine speeds.
OPERATION
A thermostatic bimetallic spring coil is located on
the front face of the viscous fan drive unit (a typical
viscous unit is shown in (Fig. 29). This spring coil
reacts to the temperature of the radiator discharge
air. It engages the viscous fan drive for higher fan
speed if the air temperature from the radiator rises
above a certain point. Until additional engine cooling
is necessary, the fan will remain at a reduced rpm
regardless of engine speed.
Only when sufficient heat is present, will the vis-
cous fan drive engage. This is when the air flowing
through the radiator core causes a reaction to the
bimetallic coil. It then increases fan speed to provide
the necessary additional engine cooling.
Once the engine has cooled, the radiator discharge
temperature will drop. The bimetallic coil again
reacts and the fan speed is reduced to the previous
disengaged speed.
DIAGNOSIS AND TESTINGÐVISCOUS FAN
DRIVE
NOISE
NOTE: It is normal for fan noise to be louder (roar-
ing) when:
²The underhood temperature is above the engage-
ment point for the viscous drive coupling. This may
occur when ambient (outside air temperature) is very
high.
²Engine loads and temperatures are high such as
when towing a trailer.
²Cool silicone fluid within the fan drive unit is
being redistributed back to its normal disengaged
(warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold
engine.
LEAKS
Viscous fan drive operation is not affected by small
oil stains near the drive bearing. If leakage appears
excessive, replace the fan drive unit.
VISCOUS DRIVE
If the fan assembly free-wheels without drag (the
fan blades will revolve more than five turns when
spun by hand), replace the fan drive. This spin test
must be performed when the engine is cool.
For the following test, the cooling system must be
in good condition. It also will ensure against exces-
sively high coolant temperature.
Fig. 28 Viscous Fan
1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY
Fig. 29 Viscous Fan DriveÐTypical
1 - VISCOUS FAN DRIVE
2 - THERMOSTATIC SPRING
3 - MOUNTING NUT TO WATER PUMP HUB
7 - 56 ENGINEBR/BE