transmission DODGE RAM 2001 Service Manual PDF

CLUTCH HOUSING
DIAGNOSIS AND TESTING - CLUTCH HOUSING
Clutch housing alignment is important to proper
clutch operation. The housing maintains alignment
between the crankshaft and transmission input
shaft. Misalignment can cause clutch noise, hard
shifting, incomplete release and chatter. It can also
result in premature wear of the pilot bearing, cover
release fingers and clutch disc. In severe cases, mis-
alignment can also cause premature wear of the
transmission input shaft and front bearing.
Housing misalignment is generally caused by
incorrect seating on the engine or transmission, loose
housing bolts, missing alignment dowels, or housing
damage. Infrequently, misalignment may also be
caused by housing mounting surfaces that are not
completely parallel. Misalignment can be corrected
with shims.
CHECKING RUNOUT
Only the NV4500 clutch housing can be
checked using the following bore and face
runout procedures. The NV3500 and NV5600
clutch housings are an integral part of the
transmission and can only be checked off the
vehicle.
MEASURING CLUTCH HOUSING BORE RUNOUT
(1) Remove the clutch housing and strut.
(2) Remove the clutch cover and disc.
(3) Replace one of the flywheel bolts with an
appropriate size threaded rod that is 10 in. (25.4 cm)
long (Fig. 14). The rod will be used to mount the dial
indicator.(4) Remove the release fork from the clutch hous-
ing.
(5) Reinstall the clutch housing. Tighten the hous-
ing bolts nearest the alignment dowels first.
(6) Mount the dial indicator on the threaded rod
and position the indicator plunger on the surface of
the clutch housing bore (Fig. 15).
(7) Rotate the crankshaft until the indicator
plunger is at the top center of the housing bore. Zero
the indicator at this point.
(8) Rotate the crankshaft and record the indicator
readings at eight points (45É apart) around the bore
(Fig. 15). Repeat the measurement at least twice for
accuracy.
(9) Subtract each reading from the one 180É oppo-
site to determine magnitude and direction of runout.
Refer to (Fig. 16) and following example.
Bore runout example:
0.000 ± (±0.007) = 0.007 in.
+0.002 ± (±0.010) = 0.012 in.
+0.004 ± (±0.005) = 0.009 in.
±0.001 ± (+0.001) = ±0.002 in. (= 0.002 inch)
In the above example, the largest difference is
0.012 in. and is called the total indicator reading
(TIR). This means that the housing bore is offset
from the crankshaft centerline by 0.006 in. (which is
1/2 of 0.012 in.).
Fig. 14 Dial Indicator Mounting Stud Or Rod
1 - 7/16 - 20 THREAD
2 - NUT
3 - STUD OR THREADED ROD
4 - 10 INCHES LONG
Fig. 15 Checking Clutch Housing Bore Runout
1 - MOUNTING STUD OR ROD
2 - DIAL INDICATOR
3 - INDICATOR PLUNGER
4 - CLUTCH HOUSING BORE
BR/BECLUTCH 6 - 11

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)

(4) Subtract the lowest reading from the highest to
determine total runout. As an example, refer to the
sample readings shown (Fig. 21). If the low reading
wasminus0.004 in. and the highest reading was
plus0.009 in., total runout is actually 0.013 inch.
(5) Total allowable face runout is 0.010 inch. If
runout exceeds this figure, runout will have to be
corrected. Refer to Correcting Clutch Housing Face
Runout.
CORRECTING CLUTCH HOUSING FACE RUNOUT
Housing face runout, on gas or diesel engines, can
be corrected by installing shims between the clutch
housing and transmission (Fig. 20). The shims can be
made from shim stock or similar materials of the
required thickness.
As an example, assume that face runout is the same
as shown in (Fig. 21) and in Step 4. In this case, three
shims will be needed. Shim thicknesses should be0.009 in. (at the 0.000 corner), 0.012 in. (at the ±0.003
corner) and 0.013 in. (at the ±0.004 corner).
After installing the clutch assembly and housing,
tighten the housing bolts nearest the alignment dow-
els first.
Clutch housing preferred bolt torques are:
²41 N´m (30 ft. lbs.) for 3/8 in. diameter bolts
²68 N´m (50 ft. lbs.) for 7/16 in. diameter bolts
²47 N´m (35 ft. lbs.) for V10 and diesel clutch
housing bolts
During final transmission installation, install the
shims between the clutch housing and transmission
at the appropriate bolt locations.
REMOVAL
(1) Raise and support vehicle.
(2) Remove transmission and transfer case, if
equipped. Refer to 21 Transmission and Transfer
Case for proper procedures.
(3) Remove the starter from the clutch housing.
(4) Remove the clutch housing dust shield from the
clutch housing.
(5) Remove clutch housing bolts and remove hous-
ing from engine (Fig. 22) and (Fig. 23).
INSTALLATION
(1) Clean housing mounting surface of engine
block with wax and grease remover.
(2) Verify that clutch housing alignment dowels
are in good condition and properly seated.
(3)
Transfer slave cylinder, release fork and boot, fork
pivot stud, and wire/hose brackets to new housing.
Fig. 19 Housing Face Measurement Points And
Sample Readings
1 - CLUTCH HOUSING FACE CIRCLE (AT RIM OF BORE)
Fig. 20 Housing Face Alignment Shims
1 - CUT/DRILL BOLT HOLE TO SIZE
2 - SHIM STOCK
3 - MAKE SHIM 1ÐINCH DIAMETER
Fig. 21 Measuring Clutch Housing Face Runout
1 - INDICATOR PLUNGER
2 - DIAL INDICATOR
3 - CLUTCH HOUSING FACE
4 - INDICATOR MOUNTING STUD OR ROD
BR/BECLUTCH 6 - 13
CLUTCH HOUSING (Continued)

(4) Lubricate release fork and pivot contact sur-
faces with MopartHigh Temperature wheel bearing
grease before installation.
(5) Align and install clutch housing on transmis-
sion (Fig. 23). Tighten housing bolts closest to align-
ment dowels first and to the following torque values:
²1/4in. diameter ªAº bolts are torqued to 4.5 N´m
(40 in.lb.).
²3/8in. diameter ªAº bolts are torqued to 47.5
N´m (35 ft.lb.).
²7/16in. diameter ªAº bolts are torqued to 68 N´m
(50 ft.lb.).
²ªBº bolts for 5.2L/5.9L applications are torqued
to 41 N´m (30 ft.lb.).
²ªBº bolts for 5.9L TD/8.0L applications are
torqued to 47.5 N´m (35 ft.lb.).
²ªCº bolts for 5.2/5.9L applications are torqued to
68 N´m (50 ft.lb.).
²ªCº bolts for 5.9L TD applications are torqued to
47.5 N´m (35 ft.lb.).
²ªCº bolts for 8.0L applications are torqued to
74.5 N´m (55 ft.lb.).
(6) Install transmission-to-engine strut after
installing clutch housing. Tighten bolt attaching
strut to clutch housing first and engine bolt last.
(7) Install the starter to the clutch housing.
(8) Install the clutch housing dust shield to the
clutch housing. Tighten the bolts to
(9) Install transmission and transfer case, if
equipped. Refer to 21Transmission and Transfer Case
for proper procedures.
CLUTCH RELEASE BEARING
DESCRIPTION
A conventional release bearing (Fig. 24) is used to
engage and disengage the clutch pressure plate assem-
bly. The clutch release bearing is mounted on the trans-
mission front bearing retainer. The bearing is attached
to the release fork, which moves the bearing into con-
tact with the clutch cover diaphragm spring.
OPERATION
The release bearing is operated by a release fork in
the clutch housing. Slave cylinder force causes the
release lever to move the release bearing into contact
with the diaphragm spring. As additional force is
applied, the bearing presses the diaphragm spring
fingers inward on the fulcrums. This action moves
the pressure plate rearward relieving clamp force on
the disc. Releasing pedal pressure removes clutch
hydraulic pressure. The release bearing then moves
away from the diaphragm spring which allows the
pressure plate to exert clamping force on the clutch
disc.
Fig. 22 Transmission/Clutch Housing - NV4500
1 - CLUTCH HOUSING
2 - NV4500 TRANSMISSION
Fig. 23 Clutch Housing Installation - NV4500
1 - ENGINE BLOCK
2 - CLUTCH DISC AND COVER
3 - CLUTCH HOUSING
4 - DUST COVER
6 - 14 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)

shaft speeds and releasing the energy back into the
system when the crankshaft slows down.
DIAGNOSIS AND TESTING - FLYWHEEL
Check flywheel runout whenever misalignment is
suspected. Flywheel runout should not exceed 0.08
mm (0.003 in.). Measure runout at the outer edge of
the flywheel face with a dial indicator. Mount the
indicator on a stud installed in place of one of the fly-
wheel bolts.
Common causes of runout are:
²heat warpage
²improper machining
²incorrect bolt tightening
²improper seating on crankshaft flange shoulder
²foreign material on crankshaft flange
Flywheel machining is not recommended. The fly-
wheel clutch surface is machined to a unique contour
and machining will negate this feature. However,
minor flywheel scoring can be cleaned up by hand with
180 grit emery, or with surface grinding equipment.
Remove only enough material to reduce scoring
(approximately 0.001 - 0.003 in.). Heavy stock removal
isnot recommended.
Replace the flywheel if scoring
is severe and deeper than 0.076 mm (0.003 in.).
Excessive stock removal can result in flywheel crack-
ing or warpage after installation; it can also weaken
the flywheel and interfere with proper clutch release.
Clean the crankshaft flange before mounting the
flywheel. Dirt and grease on the flange surface may
cock the flywheel causing excessive runout. Use new
bolts when remounting a flywheel and secure the
bolts with MopartLock And Seal. Tighten flywheel
bolts to specified torque only. Overtightening can dis-
tort the flywheel hub causing runout.
DISASSEMBLY
NOTE: If the teeth are worn or damaged, the fly-
wheel should be replaced as an assembly. This is
the recommended and preferred method of repair.
In cases where a new flywheel is not readily avail-
able, (V10/Diesel Engine only) a replacement ring
gear can be installed. The following procedure must
be observed to avoid damaging the flywheel and
replacement gear.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES WHILE CUTTING RING GEAR.
(1) Mark position of the old gear for alignment ref-
erence on the flywheel. Use a scriber for this pur-
pose.
(2) Remove the old gear by cutting most of the way
through it (at one point) with an abrasive cut-off
wheel. Then complete removal with a cold chisel or
punch.
ASSEMBLY
NOTE: The ring gear is a shrink fit on the flywheel.
This means the gear must be expanded by heating
in order to install it. The method of heating and
expanding the gear is extremely important. Every
surface of the gear must be heated at the same
time to produce uniform expansion. An oven or
similar enclosed heating device must be used. Tem-
perature required for uniform expansion is approxi-
mately 375É F.
CAUTION: Do not use an oxy/acetylene torch to
remove the old gear, or to heat and expand a new
gear. The high temperature of the torch flame can
cause localized heating that will damage the fly-
wheel. In addition, using the torch to heat a replace-
ment gear will cause uneven heating and
expansion. The torch flame can also anneal the
gear teeth resulting in rapid wear and damage after
installation.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES AND HEAT RESISTENT GLOVES
WHEN HANDLING A HEATED RING GEAR.
(1) The heated gear must be installed evenly to
avoid misalignment or distortion.
(2) Position and install the heated ring gear on the
flywheel with a shop press and a suitable press
plates.
(3) Place flywheel on work bench and let it cool in
normal shop air. Allow the ring gear to cool down
completely before installation it on the engine.
CAUTION: Do not use water or compressed air to
cool the flywheel. The rapid cooling produced by
water or compressed air will distort or crack the
new gear.
PILOT BEARING
DESCRIPTION
Vehicles equipped with a manual transmission uti-
lize a pilot bearing. This bearing is located in the
back of the engine crankshaft. Depending on the type
of engine or application, the pilot bearing can be a
solid soft metallic bushing or a fully caged needle
bearing. The pilot bearing's main functions are to
support the transmission input shaft, maintain
proper alignment of the clutch assembly and allow
the transmission main shaft to rotate at a different
speed than the engine mounted crankshaft.
BR/BECLUTCH 6 - 17
FLYWHEEL (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

Coolant flow circuits for the 5.9L diesel engine are
shown in (Fig. 3).
DESCRIPTIONÐHOSE CLAMPS
The cooling system utilizes both worm drive and
spring type hose clamps. If a spring type clamp
replacement is necessary, replace with the original
Mopartequipment spring type clamp.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only a original equipment clamp
with matching number or letter (Fig. 4).
OPERATIONÐHOSE CLAMPS
The worm type hose clamp uses a specified torque
value to maintain proper tension on a hose connec-
tion.
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
Fig. 1 Engine Cooling System Flow
1 - HEATER
2 - BYPASS*3 - CROSSFLOW RADIATOR
Fig. 2 Cooling System Components 5.9L Diesel
Engine
1 - RADIATOR CAP
2 - AUXILIARY TRANSMISSION OIL COOLER
3 - CHARGE AIR COOLER
4 - RADIATOR LOWER HOSE
5 - OVERFLOW/RESERVOIR BOTTLE
6 - FAN SHROUD
7 - RADIATOR UPPER HOSE
8 - CONSTANT TENSION CLAMP
7 - 2 COOLINGBR/BE
COOLING (Continued)

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)