(5) Remove pulley bolt. Remove pulley from ten-
sioner.
INSTALLATION
(1) Install pulley and pulley bolt to tensioner.
Tighten bolt to 61 N´m (45 ft. lbs.) torque.
(2) Install tensioner assembly to mounting
bracket. An indexing tab is located on back of ten-
sioner. Align this tab to slot in mounting bracket.
Tighten nut to 67 N´m (50 ft. lbs.) torque.
(3) Connect all wiring to ignition coil.
CAUTION: To prevent damage to coil case, coil
mounting bolts must be torqued.
(4) Install coil to coil bracket. If nuts and bolts are
used to secure coil to coil bracket, tighten to 11 N´m
(100 in. lbs.) torque. If coil mounting bracket has
been tapped for coil mounting bolts, tighten bolts to 5
N´m (50 in. lbs.) torque.
(5) Install drive belt. (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
(6) Check belt indexing marks (Fig. 4).
BELT TENSIONERS - 5.9L
DIESEL
DESCRIPTION
Drive belts on all engines are equipped with a
spring loaded automatic belt tensioner (Fig. 5). 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.
Fig. 4 Tensioner Indexing Marks And Mounting Nut
1 - TENSIONER ASSEMBLY
2 - TENSIONER MOUNTING NUT
3 - INDEXING ARROW
4 - INDEXING MARK
Fig. 5 Belt
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - AUTOMATIC TENSIONER
6 - A/C COMPRESSOR
7 - 24 ACCESSORY DRIVEDR
BELT TENSIONERS - 5.9L (Continued)
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. 6) and
remove tensioner.
INSTALLATION
(1) Install tensioner assembly to mounting
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 BELTS - 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. 7), 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. 7). 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.
Fig. 6 AUTOMATIC BELT TENSIONER DIESEL
ENGINE-TYPICAL
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - AUTOMATIC TENSIONER
6 - A/C COMPRESSOR
Fig. 7 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
DRACCESSORY DRIVE 7 - 25
BELT TENSIONERS - 5.9L DIESEL (Continued)
DRIVE BELTS - 5.9L
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. 10), 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. 10). 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.
Fig. 8 BELT ROUTING 3.7L / 4.7L
1 - GENERATOR PULLEY
2 - ACCESSORY DRIVE BELT
3 - POWER STEERING PUMP PULLEY
4 - CRANKSHAFT PULLEY
5 - IDLER PULLEY
6 - TENSIONER
7 - A/C COMPRESSOR PULLEY
8 - WATER PUMP PULLEY
Fig. 9 Accessory Drive Belt Wear Indicator±4.7L
Engine
1 - AUTOMATIC TENSIONER ASSEMBLY
Fig. 10 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
7 - 28 ACCESSORY DRIVEDR
DRIVE BELTS - 3.7L / 4.7L (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
NOISE
(Objectionable 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
REMOVAL
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.
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.
Drive belts on these engines are equipped with a
spring loaded automatic belt tensioner (Fig. 11). This
belt tensioner will be used on all belt configurations,
such as with or without power steering or air condi-
tioning. For more information, (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/BELT TENSIONERS -
DESCRIPTION).
(1) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 11).
(2) Rotate tensioner assembly clockwise (as viewed
from front) until tension has been relieved from belt.
(3) Remove belt from idler pulley first.
(4) Remove belt from vehicle.
Fig. 11 Belt Tensioner - 5.9L Gas Engines
1 - IDLER PULLEY
2 - TENSIONER
3 - FAN BLADE
7 - 30 ACCESSORY DRIVEDR
DRIVE BELTS - 5.9L (Continued)
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. 12) (Fig. 13) for correct
engine belt routing. The correct belt with correct
length must be used.
(1) Position drive belt over all pulleysexceptidler
pulley. This pulley is located between generator and
A/C compressor.
(2) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 11).
(3) Rotate socket/wrench clockwise. Place belt over
idler pulley. Let tensioner rotate back into place.
Remove wrench. Be sure belt is properly seated on
all pulleys.
(4) Check belt indexing marks (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/BELT TENSIONERS -
DESCRIPTION).
DRIVE BELTS - 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. 14), 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. 14). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Fig. 12 Belt Routing - 5.9L Engines with A/C
1 - GENERATOR PULLEY
2 - A/C PULLEY
3 - POWER STEERING PULLEY
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - TENSIONER PULLEY
7 - IDLER PULLEY
Fig. 13 Belt Routing - 5.9L Engines Without A/C
1 - GENERATOR PULLEY
2 - IDLER PULLEY
3 - POWER STEERING PULLEY
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - TENSIONER PULLEY
DRACCESSORY DRIVE 7 - 31
DRIVE BELTS - 5.9L (Continued)
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.
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.displays the
tensioner for vehicles without air conditioning.
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 mayoverheat due to water pump rotating in wrong
direction. Refer to (Fig. 15) 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. 15 Belt Routing±5.9L Diesel Engine
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
7 - 34 ACCESSORY DRIVEDR
DRIVE BELTS - 5.9L DIESEL (Continued)
(6) Install the radiator upper hose to the thermo-
stat housing.
CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
the engine may overheat due to the water pump
rotating in wrong direction. Refer to (Fig. 24) for the
correct 5.9L engine belt routing. The correct belt
with correct length must be used.
(7) Air Conditioned vehicles; Install the generator.
Tighten the bolts to 41 N´m (30 ft. lbs.).
(8) Install the support bracket (generator mount-
ing bracket-to-intake manifold). (Fig. 19). Tighten the
bolts to 54 N´m (40 ft. lbs.).
(9) Install the accessory drive belt (Fig. 20)(Refer
to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION).
(10) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(11) Connect battery negative cable.
(12) Start and warm the engine. Check for leaks.
ENGINE COOLANT
THERMOSTAT - 3.7L/4.7L
DESCRIPTION
CAUTION: Do not operate the engine without a ther-
mostat, except for servicing or testing.
A pellet-type thermostat controls the operating
temperature of the engine by controlling the amount
of coolant flow to the radiator. On all engines the
thermostat is closed below 195ÉF (90ÉC). Above this
temperature, coolant is allowed to flow to the radia-
tor. This provides quick engine warm up and overall
temperature control. On the 3.7L4.7L engine the
thermostat is designed to block the flow of the cool-
ant bypass journal by 50% instead of completely
blocking the flow. This design controls coolant tem-
perature more accurately (Fig. 25).
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
Fig. 23 Thermostat PositionÐ5.9L EnginesFig. 24 Belt Routing ± 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
7 - 50 ENGINEDR
ENGINE COOLANT THERMOSTAT- 5.7L/5.9L (Continued)
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW
Use the following procedure to determine if coolant
is flowing through the cooling system.
(1) Idle engine until operating temperature is
reached. If the upper radiator hose is warm to the
touch, the thermostat is opening and coolant is flow-
ing to the radiator.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. USING A RAG TO
COVER THE RADIATOR PRESSURE CAP, OPEN
RADIATOR CAP SLOWLY TO THE FIRST STOP. THIS
WILL ALLOW ANY BUILT-UP PRESSURE TO VENT
TO THE RESERVE/OVERFLOW TANK. AFTER PRES-
SURE BUILD-UP HAS BEEN RELEASED, REMOVE
CAP FROM FILLER NECK.
(2) Drain a small amount of coolant from the radi-
ator until the ends of the radiator tubes are visible
through the filler neck. Idle the engine at normal
operating temperature. If coolant is flowing past the
exposed tubes, the coolant is circulating.
REMOVAL
(1) Disconnect battery negative cables.WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM THE COOL-
ANT CAN OCCUR.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP. ALWAYS WEAR SAFETY GLASSES WHEN
SERVICING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter and the correct
width.
(3) Remove the hose clamps and hoses from radia-
tor.
(4) Remove the coolant reserve/overflow tank hose
from the radiator filler neck.
(5) Remove the coolant reserve/overflow tank
(5.9L) or the coolant degas container(3.7L/4.7L) from
the fan shroud (pull straight up). The tank slips into
slots on the fan shroud.
(6) Unclip the power steering hoses from the fan
shroud.
(7) Disconnect the electrical connectors at the
windshield washer reservoir tank and remove the
tank.
(8) Remove the fan shroud mounting bolts and pull
up and out of the radiator tank clips (Fig. 33). Posi-
tion shroud rearward over the fan blades towards
engine.
(9) Disconnect the transmission cooler lines from
the transmission cooler, then plug the transmission
lines and cooler to prevent leakage.
(10) Disconnect the power steering lines from the
power steering cooler, then plug the power steering
lines and cooler to prevent leakage.
(11) Remove the two radiator upper mounting
bolts (Fig. 34).
(12) Lift the radiator straight up and out of the
engine compartment. Take care not to damage cool-
ing fins or tubes on the radiator and oil coolers when
removing.
Fig. 32 Radiator Ð Typical
1 - SCREW
2 - SCREW
3 - LOWER MOUNT
4 - RADIATOR
5 - DRAINCOCK
6 -LOWER MOUNT
DRENGINE 7 - 57
RADIATOR (Continued)