5.9l DODGE RAM 1500 1998 2.G User Guide

ACCESSORY DRIVE
TABLE OF CONTENTS
page page
BELT TENSIONER - 3.7L / 4.7L
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................22
BELT TENSIONER-5.7L
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................23
BELT TENSIONER - 5.9L DIESEL
DESCRIPTION.........................23
OPERATION...........................23REMOVAL.............................23
INSTALLATION.........................24
DRIVE BELT - 3.7L / 4.7L
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT.........................24
REMOVAL.............................26
INSTALLATION.........................26
DRIVE BELT - 5.9L DIESEL
DIAGNOSIS AND TESTINGÐACCESSORY
DRIVE BELT.........................27
REMOVAL.............................29
INSTALLATION.........................29
BELT TENSIONER - 3.7L / 4.7L
DESCRIPTION
Correct drive belt tension is required to ensure
optimum performance of the belt driven engine acces-
sories. If specified tension is not maintained, belt
slippage may cause; engine overheating, lack of
power steering assist, loss of air conditioning capac-
ity, reduced generator output rate, and greatly
reduced belt life.
It is not necessary to adjust belt tension on the
3.7L or 4.7L engine. These engines are equipped with
an automatic belt tensioner (Fig. 1). The tensioner
maintains correct belt tension at all times. Due to
use of this belt tensioner, do not attempt to use a belt
tension gauge on 3.7L or 4.7L engines.
OPERATION
The automatic belt tensioner maintains belt ten-
sion by using internal spring pressure, a pivoting
arm and pulley to press against the drive belt.
REMOVAL
On 3.7L and 4.7L engines, the tensioner is
equipped with an indexing tang on back of ten-
sioner and an indexing stop on tensioner hous-
ing. If a new belt is being installed, tang must
be within approximately 24 mm (.94 inches) of
indexing stop. Belt is considered new if it has
been used 15 minutes or less.
If the above specification cannot be met, check for:²The wrong belt being installed (incorrect length/
width)
²Worn bearings on an engine accessory (A/C com-
pressor, power steering pump, water pump, idler pul-
ley or generator)
²A pulley on an engine accessory being loose
²Misalignment of an engine accessory
²Belt incorrectly routed.
NOTE: A used belt should be replaced if tensioner
indexing arrow has moved to the minimum tension
indicator. Tensioner travel stops at this point.
Fig. 1 AUTOMATIC BELT TENSIONER
1 - AUTOMATIC TENSIONER ASSEMBLY
DRACCESSORY DRIVE 7 - 21

INSTALLATION
(1) Install tensioner on to the mounting bracket.
Tighten bolt to 41 N´m (30 ft. lbs.).
(2) Install tensioner and bracket assembly
(3) Install accessory drive belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
BELT TENSIONER - 5.9L
DIESEL
DESCRIPTION
Drive belts on all engines are equipped with a
spring loaded automatic belt tensioner (Fig. 4). This
tensioner maintains constant belt tension at all times
and requires no maintenance or adjustment.
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner.
OPERATION
WARNING: THE AUTOMATIC BELT TENSIONER
ASSEMBLY IS SPRING LOADED. DO NOT ATTEMPT
TO DISASSEMBLE THE TENSIONER ASSEMBLY.
The automatic belt tensioner maintains correct belt
tension using a coiled spring within the tensioner
housing. The spring applies pressure to the tensioner
arm pressing the arm into the belt, tensioning the
belt.
REMOVAL
WARNING: BECAUSE OF HIGH SPRING PRES-
SURE, DO NOT ATTEMPT TO DISASSEMBLE AUTO-
MATIC TENSIONER. UNIT IS SERVICED AS AN
ASSEMBLY.
(1) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(2) Remove tensioner mounting bolt (Fig. 5) and
remove tensioner.
Fig. 4 Accessory Drive Belt - 5.9L Diesel
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - RADIATOR FAN PULLEY
6 - CRANKSHAFT
7 - AUTOMATIC TENSIONER
8 - A/C COMPRESSOR
Fig. 5 AUTOMATIC BELT TENSIONER 5.9L DIESEL
ENGINE
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - RADIATOR FAN PULLEY
6 - CRANKSHAFT
7 - AUTOMATIC TENSIONER
8 - A/C COMPRESSOR
DRACCESSORY DRIVE 7 - 23
BELT TENSIONER-5.7L (Continued)

INSTALLATION
(1) Install tensioner assembly to water inlet
bracket. A dowel is located on back of tensioner. Align
this dowel to hole in tensioner mounting bracket.
Tighten bolt to 43 N´m (32 ft. lbs.) torque.
(2) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
DRIVE BELT - 3.7L / 4.7L
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 6), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 6). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt toresolve a noise condition, inspect all of the accessory
drive pulleys for alignment, glazing, or excessive end
play.
ACCESSORY DRIVE BELT DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
RIB CHUNKING (One or more ribs
has separated from belt body)1. Foreign objects imbedded in
pulley grooves.1. Remove foreign objects from
pulley grooves. Replace belt.
2. Installation damage 2. Replace belt
RIB OR BELT WEAR 1. Pulley misaligned 1. Align pulley(s)
2. Abrasive environment 2. Clean pulley(s). Replace belt if
necessary
3. Rusted pulley(s) 3. Clean rust from pulley(s)
4. Sharp or jagged pulley groove
tips4. Replace pulley. Inspect belt.
5. Belt rubber deteriorated 5. Replace belt
Fig. 6 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
7 - 24 ACCESSORY DRIVEDR
BELT TENSIONER - 5.9L DIESEL (Continued)

DRIVE BELT - 5.9L DIESEL
DIAGNOSIS AND TESTINGÐACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 9), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 9). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt to
resolve a noise condition, inspect all of the accessory
drive pulleys for alignment, glazing, or excessive end
play.
ACCESSORY DRIVE BELT DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
RIB CHUNKING (One or more ribs
has separated from belt body)1. Foreign objects imbedded in
pulley grooves.1. Remove foreign objects from
pulley grooves. Replace belt.
2. Installation damage 2. Replace belt
RIB OR BELT WEAR 1. Pulley misaligned 1. Align pulley(s)
2. Abrasive environment 2. Clean pulley(s). Replace belt if
necessary
3. Rusted pulley(s) 3. Clean rust from pulley(s)
4. Sharp or jagged pulley groove
tips4. Replace pulley. Inspect belt.
5. Belt rubber deteriorated 5. Replace belt
BELT SLIPS 1. Belt slipping because of
insufficient tension1. Inspect/Replace tensioner if
necessary
2. Belt or pulley exposed to
substance that has reduced friction
(belt dressing, oil, ethylene glycol)2. Replace belt and clean pulleys
3. Driven component bearing failure
(seizure)3. Replace faulty component or
bearing
4. Belt glazed or hardened from
heat and excessive slippage4. Replace belt.
Fig. 9 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
DRACCESSORY DRIVE 7 - 27

CONDITION POSSIBLE CAUSES CORRECTION
LONGITUDAL BELT CRACKING 1. Belt has mistracked from pulley
groove1. Replace belt
2. Pulley groove tip has worn away
rubber to tensile member2. Replace belt
9GROOVE JUMPING9
(Belt does not maintain correct
position on pulley)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Pulley(s) not within design
tolerance2. Replace pulley(s)
3. Foreign object(s) in grooves 3. Remove foreign objects from
grooves
4. Pulley misalignment 4. Align component
5. Belt cordline is broken 5. Replace belt
BELT BROKEN
(Note: Identify and correct problem
before new belt is installed)1. Incorrect belt tension 1. Replace Inspect/Replace
tensioner if necessary
2. Tensile member damaged during
belt installation2. Replace belt
3. Severe misalignment 3. Align pulley(s)
4. Bracket, pulley, or bearing failure 4. Replace defective component
and belt
NOISE (Objectional squeal, squeak,
or rumble is heard or felt while drive
belt is in operation)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Bearing noise 2. Locate and repair
3. Belt misalignment 3. Align belt/pulley(s)
4. Belt to pulley mismatch 4. Install correct belt
5. Driven component induced
vibration5. Locate defective driven
component and repair
TENSION SHEETING FABRIC
FAILURE
(Woven fabric on outside,
circumference of belt has cracked or
separated from body of belt)1. Tension sheeting contacting
stationary object1. Correct rubbing condition
2. Excessive heat causing woven
fabric to age2. Replace belt
3. Tension sheeting splice has
fractured3. Replace belt
CORD EDGE FAILURE
(Tensile member exposed at edges
of belt or separated from belt body)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Belt contacting stationary object 2. Replace belt
3. Pulley(s) out of tolerance 3. Replace pulley
4. Insufficient adhesion between
tensile member and rubber matrix4. Replace belt
NOTE: The engine speed sensor face is very close
to the accessory drive belt. Inspect engine speed
sensor and wire harness for damage when acces-sory drive belt has been replaced due to failure or
abnormal conditions.
7 - 28 ACCESSORY DRIVEDR
DRIVE BELT - 5.9L DIESEL (Continued)

REMOVAL
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner. Refer to Automatic Belt
Tensioner in this group.
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label.This label is located in
the engine compartment.
Drive belts on diesel engines are equipped with a
spring loaded automatic belt tensioner.
This belt tensioner will be used on all belt config-
urations, such as with or without air conditioning.
For more information, (Refer to 7 - COOLING/AC-
CESSORY DRIVE/BELT TENSIONERS - DESCRIP-
TION).
(1) A 1/2 inch square hole is provided in the auto-
matic belt tensioner. Attach a 1/2 inch drive-long
handle ratchet to this hole.(2) Rotate ratchet and tensioner assembly clock-
wise (as viewed from front) until tension has been
relieved from belt.
(3) Remove belt from water pump pulley first.
(4) Remove belt from vehicle.
INSTALLATION
CAUTION: When installing the 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. 10) or (Fig. 11)for correct
engine belt routing. The correct belt with correct
length must be used.
(1) Position drive belt over all pulleysexcept
water pump pulley.
(2) Attach a 1/2 inch ratchet to tensioner.
(3) Rotate ratchet and belt tensioner clockwise.
Place belt over water pump pulley. Let tensioner
rotate back into place. Remove ratchet. Be sure belt
is properly seated on all pulleys.
Fig. 10 Belt Routing ± 5.9L Diesel Engine With A/C
1 - GENERATOR PULLEY
2 - WATER PUMP PULLEY
3 - IDLER PULLEY
4 - POWER STEERING PUMP PULLEY
5 - RADIATOR FAN PULLEY
6 - CRANKSHAFT PULLEY
7 - AUTOMATIC TENSIONER
8 - A/C COMPRESSOR PUMP PULLEY
Fig. 11 Belt Routing - 5.9L Diesel Engine Without
A/C
1 - GENERATOR PULLEY
2 - WATER PUMP PULLEY
3 - IDLER PULLEY
4 - POWER STEERING PUMP PULLEY
5 - RADIATOR FAN PULLEY
6 - CRANKSHAFT PULLEY
7 - AUTOMATIC TENSIONER
DRACCESSORY DRIVE 7 - 29
DRIVE BELT - 5.9L DIESEL (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION
DESCRIPTION - ENGINE COOLANT.......31
DESCRIPTION - HOAT COOLANT.........32
OPERATION...........................33
COOLANT RECOVERY CONTAINER- GAS
ENGINES
DESCRIPTION.........................33
OPERATION...........................33
REMOVAL.............................33
INSTALLATION.........................33
RADIATOR FAN - GAS ENGINES
REMOVAL.............................33
CLEANING............................34
INSPECTION..........................34
INSTALLATION.........................34
RADIATOR FAN - 5.9L DIESEL
REMOVAL.............................35
CLEANING............................35
INSPECTION..........................35
INSTALLATION.........................36
ENGINE BLOCK HEATER
DESCRIPTION.........................36
OPERATION...........................36
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER ............................36
REMOVAL.............................37
INSTALLATION.........................37
ENGINE BLOCK HEATER - 5.9L DIESEL
DESCRIPTION.........................37
OPERATION...........................38
REMOVAL.............................38
INSTALLATION.........................38
ENGINE COOLANT TEMPERATURE SENSOR
DESCRIPTION.........................38
OPERATION...........................38
REMOVAL.............................39
INSTALLATION.........................41
ENGINE COOLANT THERMOSTAT- 5.7L
DESCRIPTION.........................41
OPERATION...........................41
DIAGNOSIS AND TESTINGÐTHERMOSTAT . . . 42
REMOVAL.............................42
INSTALLATION.........................43
ENGINE COOLANT THERMOSTAT - 3.7L/4.7L
DESCRIPTION.........................44
OPERATION...........................44
DIAGNOSIS AND TESTINGÐTHERMOSTAT . . . 44
REMOVAL.............................45INSTALLATION.........................45
ENGINE COOLANT THERMOSTAT - 5.9L
DIESEL
DESCRIPTION.........................46
OPERATION...........................46
DIAGNOSIS AND TESTING - THERMOSTAT . . . 47
REMOVAL.............................47
INSTALLATION.........................47
ENGINE COOLANT THERMOSTAT - 8.0L
DESCRIPTION.........................48
OPERATION...........................48
DIAGNOSIS AND TESTING - THERMOSTAT . . . 48
REMOVAL.............................49
INSTALLATION.........................49
FAN DRIVE VISCOUS CLUTCH-GAS ENGINES
DESCRIPTION.........................50
OPERATION...........................50
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE..............................50
FAN DRIVE VISCOUS CLUTCH - 5.9L DIESEL
DESCRIPTION.........................52
OPERATION...........................52
DIAGNOSIS AND TESTING -
ELECTRONICALLY CONTROLLED VISCOUS
FAN DRIVE..........................52
RADIATOR-3.7L/4.7L/5.7L
DESCRIPTION.........................54
OPERATION...........................54
DIAGNOSIS AND TESTING - RADIATOR
COOLANT FLOW......................54
REMOVAL.............................54
CLEANING............................55
INSPECTION..........................55
INSTALLATION.........................55
RADIATOR - 5.9L DIESEL
DESCRIPTION.........................56
OPERATION...........................56
DIAGNOSIS AND TESTING - RADIATOR
COOLANT FLOW......................56
REMOVAL.............................56
CLEANING............................56
INSPECTION..........................56
INSTALLATION.........................57
RADIATOR PRESSURE CAP
DESCRIPTION.........................57
OPERATION...........................58
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - RADIATOR
CAP-TO-FILLER NECK SEAL.............58
7 - 30 ENGINEDR

DIAGNOSIS AND TESTING - RADIATOR
CAP................................58
CLEANING............................59
INSPECTION..........................59
WATER PUMP - 3.7L/4.7L
DESCRIPTION
DESCRIPTION - WATER PUMP...........59
DESCRIPTION - WATER PUMP BYPASS....59
OPERATION
OPERATIONÐWATER PUMP............60
OPERATION - WATER PUMP BYPASS.....60
REMOVAL.............................60
CLEANING............................61
INSPECTION..........................61
INSTALLATION.........................61
WATER PUMP - 5.9L DIESEL
DESCRIPTION.........................62OPERATION...........................62
DIAGNOSIS AND TESTINGÐWATER PUMP . . . 62
REMOVAL.............................62
CLEANING............................62
INSPECTION..........................62
INSTALLATION.........................62
WATER PUMP - 5.7L
REMOVAL.............................63
INSTALLATION.........................63
WATER PUMP - 8.0L
DIAGNOSIS AND TESTING - WATER PUMP . . . 63
REMOVAL.............................64
CLEANING............................66
INSPECTION..........................66
INSTALLATION.........................66
COOLANT
DESCRIPTION
DESCRIPTION - ENGINE COOLANT
ETHYLENE-GLYCOL MIXTURES
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
year/100,000 Mile Formula (ethylene-glycol base cool-
ant with corrosion inhibitors called HOAT, for Hybrid
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain a freeze
point of -37ÉC (-35ÉF).
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The antifreeze concentrationmust
alwaysbe a minimum of 44 percent, year-round in
all climates.If percentage is lower than 44 per-
cent, engine parts may be eroded by cavitation,
and cooling system components may be
severely damaged by corrosion.Maximum protec-
tion against freezing is provided with a 68% anti-
freeze concentration, which prevents freezing down to
-67.7É C (-90É F). A higher percentage will freeze at a
warmer temperature. Also, a higher percentage of
antifreeze can cause the engine to overheat becausethe specific heat of antifreeze is lower than that of
water.
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149É C (300É F). This temperature is hot enough to
melt plastic and soften solder. The increased temper-
ature can result in engine detonation. In addition,
100 percent ethylene-glycol freezes at 22É C (-8É F ).
PROPYLENE-GLYCOL MIXTURES
It's overall effective temperature range is smaller
than that of ethylene-glycol. The freeze point of 50/50
propylene-glycol and water is -32É C (-26É F). 5É C
higher than ethylene-glycol's freeze point. The boiling
point (protection against summer boil-over) of propy-
lene-glycol is 125É C (257ÉF)at96.5 kPa (14 psi),
compared to 128É C (263É F) for ethylene-glycol. Use
of propylene-glycol can result in boil-over or freeze-up
on a cooling system designed for ethylene-glycol. Pro-
pylene glycol also has poorer heat transfer character-
istics than ethylene glycol. This can increase cylinder
head temperatures under certain conditions.
Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
DRENGINE 7 - 31

(4) Install the fan blade/viscous fan drive assembly
to the water pump shaft (Fig. 3). Tighten mounting
nut to 50 N´m (37 ft. lbs.).
(5) Install the coolant reserve/overflow container
to the fan shroud.
(6) Connect the negative battery cable.
NOTE:
Viscous Fan Drive Fluid Pump Out Requirement:
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 electronically controlled viscous
fan drive is replaced because of mechanical dam-
age, the cooling fan blades should also be
inspected. Inspect for fatigue cracks, or chipped
blades that could have resulted from excessive
vibration. Replace fan blade assembly if any of
these conditions are found. Also inspect wiring har-
ness and connectors for damage.
(1) Disconnect the battery negative cables.
(2) Remove coolant recovery container (Refer to 7 -
COOLING/ENGINE/COOLANT RECOVERY CON-
TAINER - REMOVAL).
(3) Using a fastener removal tool, remove the two
push pin fasteners from the fan shroud lower half.
(4) Unseat the four fastening tabs and remove the
lower radiator shroud.
(5) Disconnect electrical connector.
(6) Remove the electronically controlled viscous fan
drive electrical wire from the upper radiator shroud.
(7) Using a fastener removal tool, remove the wir-
ing harness bracket from the upper radiator shroud.
CAUTION: Do not remove the fan pulley bolts. This
pulley is under spring tension.
(8) The electronically controlled viscous fan drive/
fan blade assembly is attached (threaded) to the fan
pulley shaft (Fig. 4). Remove the fan blade/fan drive
assembly from fan pulley by turning the mounting
nut counterclockwise (as viewed from front). Threads
on the viscous fan drive areRIGHT-HAND.A36
MM Fan Wrench can be used. Place a bar or screw-
driver between the fan pulley bolts to prevent pulley
from rotating.
(9) Remove the upper radiator shroud mounting
bolts.(10) Remove the fan shroud and the fan blade/vis-
cous drive as an assembly from vehicle.
CAUTION: The electronically controlled viscous fan
drive is vibration and impact sensitive, especially at
the electrical connectors. Do not drop the unit.
(11) Remove the six fan blade-to-viscous fan drive
mounting bolts.
(12) Inspect the fan for cracked, chipped or dam-
aged fan blades.
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.
Fig. 4 Fan Blade/Viscous Fan Drive - 5.9L Diesel
1 - ELECTRICAL CONNECTOR
2 - VISCOUS FAN DRIVE
3 - FAN BLADE
4 - BOLT (6)
5 - RADIATOR FAN PULLEY
DRENGINE 7 - 35
RADIATOR FAN - GAS ENGINES (Continued)

INSTALLATION
(1) Install fan blade assembly to electrically con-
trolled viscous fan drive. Tighten mounting bolts to
24 N´m (18 ft. lbs.) torque.
(2) Position the fan blade/viscous fan drive to the
vehicle as an assembly.
(3) Install the viscous fan drive assembly onto fan
pulley hub shaft (Fig. 4). Tighten mounting nut to
115 N´m (85 ft. lbs.) torque.
(4) Install upper fan shroud. Make sure the upper
shroud locks into the tabs on the lower radiator.
(5) Install two upper shroud mounting bolts.
Tighten to 11.8 N´m (105 in. lbs.) torque.
(6) Position the electronically controlled viscous
fan drive wiring into the channel in the upper fan
shroud (Fig. 5). Make sure the wiring is not pinched.
(7) Install the lower fan shroud into position and
verify the two locking tabs have seated.
(8) Install two push pin fasteners to lock lower fan
shroud to the main assembly.
NOTE: Verify that the fan drive electrical wire does
not interfere with fan blade travel when the fan
blade is spun by hand.
(9) Connect the wiring harness connector and
install the harness bracket to the upper radiator
shroud.(10) Install the coolant recovery container (Refer to
7 - COOLING/ENGINE/COOLANT RECOVERY
CONTAINER - INSTALLATION).
(11) Connect the battery negative cables.
NOTE:
Viscous Fan Drive Fluid Pump Out Requirement:
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.
ENGINE BLOCK HEATER
DESCRIPTION
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
An optional engine block heater is available with
all models. The heater is equipped with a power cord.
The cord is attached to an engine compartment com-
ponent with tie-straps. The heater warms the engine
providing easier engine starting and faster warm-up
in low temperatures. The heater is mounted in a core
hole of the engine cylinder block in place of a freeze
plug with the heating element immersed in engine
coolant. The 3.7L/4.7L gas powered engines have the
block heater located to the rear on the right side of
the engine (Fig. 6).
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to a
grounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element.
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER
If the unit does not operate, possible causes can be
either the power cord or the heater element. Test the
power cord for continuity with a 110-volt voltmeter or
110-volt test light. Test heater element continuity
with an ohmmeter or a 12-volt test light.
CAUTION: To prevent damage, the power cord must
be secured in it's retainer clips and away from any
components that may cause abrasion or damage,
such as linkages, exhaust components, etc.
Fig. 5 Electronically Controlled Viscous Fan Drive
Wiring
1 - UPPER SHROUD
2 - WIRING
3 - GROMMET
7 - 36 ENGINEDR
RADIATOR FAN - 5.9L DIESEL (Continued)