2002 JEEP GRAND CHEROKEE radiator

SPECIAL TOOLS
POWER STEERING PUMP
FLUID COOLER
DESCRIPTION
4.7L models of this vehicle are equipped with a
cooler for the power steering system fluid. The power
steering fluid cooler is located at the front of the
vehicle. It is mounted to the radiator support just
forward of the air-conditioning condenser and just
rearward of the front fascia (Fig. 6). The cooler is
positioned so it is in the air flow through the front
fascia of the vehicle.
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Drain the power steering fluid out of the reser-
voir.
(3) Remove the front fascia grille assembly,(Refer
to 13 - FRAMES & BUMPERS/BUMPERS/FRONT
FASCIA - REMOVAL).
(4) Remove the grille opening reinforcement panel
(5) Place a drain pan under the cooler.
(6) Disconnect the lower hose at cooler (Fig. 6).
(7) Disconnect the upper hose at cooler (Fig. 6).
(8) Remove the three cooler mounting bolts (Fig.
6).
(9) Remove the cooler from the vehicle.
Analyzer Set, Power Steering Flow/Pressure 6815
Adapters, Power Steering Flow/Pressure Tester
6893
4.7L HYDRAULIC POWER STEERING TEST
ADAPTER KIT - 8630
Puller C-4333
Installer, Power Steering Pulley C-4063B
Fig. 6 POWER STEERING FLUID COOLER
1 - POWER STEERING COOLER
2 - POWER STEERING COOLER LINES CLIP
19 - 36 PUMPWJ
PUMP (Continued)

(5) Disconnect the rubber hose from the power
steering reservoir (Fig. 12).
(6) Remove the hose from the vehicle.
REMOVAL - 3/8(GEAR OUTLET HOSE
(1) Drain the power steering fluid from the reser-
voir.
(2) Remove the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
REMOVAL).
(3) Raise and support the vehicle.
(4) Disconnect the rubber hose from the steering
cooler inlet tube (Fig. 11).
(5) Disconnect the metal tube from the power
steering gear (Fig. 11).
(6) Remove the hose from the vehicle.
REMOVAL - INLET COOLER HOSE
(1) Disconnect negative battery cable at battery.
(2) Drain the power steering fluid out of the reser-
voir.
(3) Remove the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
REMOVAL).
(4) Remove the front fascia grille assembly,(Refer
to 13 - FRAMES & BUMPERS/BUMPERS/FRONT
FASCIA - REMOVAL).
(5) Remove the grille opening reinforcement panel
(6) Place a drain pan under the cooler.
(7) Disconnect the lower hose at cooler (Fig. 6).
(8) Disconnect the cooler hose at the gear.
(9) Remove the bracket holding the cooler hoses
(Fig. 13).
(10) Remove the cooler hose from the vehicle.
REMOVAL - OUTLET COOLER HOSE
(1) Disconnect negative battery cable at battery.
(2) Drain the power steering fluid out of the reser-
voir.
(3) Remove the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
REMOVAL).
(4) Remove the front fascia grille assembly,(Refer
to 13 - FRAMES & BUMPERS/BUMPERS/FRONT
FASCIA - REMOVAL).
(5) Remove the grille opening reinforcement panel
(6) Place a drain pan under the cooler.
(7) Disconnect the upper hose at cooler (Fig. 6).
(8) Disconnect the cooler hose at the reservoir.
(9) Remove the bracket holding the cooler hoses
(Fig. 13).
(10) Remove the cooler hose from the vehicle.
INSTALLATION
INSTALLATION - 1/2(PRESSURE HOSE
NOTE: Lubrication and a new o-ring must be used
when reinstalling.
(1) Install the hoses to the vehicle.
(2) Reconnect the high pressure hose to the power
steering pump (Fig. 8) Tighten the hose to 22.5 N´m
(17 ft.lbs.).
(3) Reconnect the high pressure hose to the
hydraulic fan motor (Fig. 8) Tighten the hose to 22.5
N´m (17 ft.lbs.).
(4) Install the hose to the clipped position on the
fan shroud.
(5) Install the metal skid plate.
(6) Install the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
INSTALLATION).
(7) Refill the power steering fluid and bleed the
system,(Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE).
INSTALLATION - 1/2(RETURN HOSE
(1) Install the hoses to the vehicle.
(2) Reconnect the rubber return hose to the power
steering reservoir (Fig. 9) Tighten the hose clamp.
(3) Reconnect the rubber return hose to the
hydraulic fan motor (Fig. 9) Tighten the hose.
(4) Install the metal skid plate.
(5) Install the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
INSTALLATION).
(6) Refill the power steering fluid and bleed the
system,(Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE).
Fig. 13 COOLER HOSES MOUNTING BRACKET
1 - RADIATOR
2 - COOLER HOSES MOUNTING BRACKET
2 - COOLER HOSE
19 - 40 PUMPWJ
HOSES - 4.7L (Continued)

(1) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
(2) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to reverse flush cooler and lines after
repair
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary coolers
as well. The torque converter should also be replaced
whenever a failure generates sludge and debris. This
is necessary because normal converter flushing proce-
dures will not remove all contaminants.
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transmission vent where it may be mis-
taken for a leak.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
Fluid level is checked with the engine running at
curb idle speed, the transmission in NEUTRAL and
the transmission fluid at normal operating tempera-
ture.The engine should be running at idle
speed for at least one minute, with the vehicle
on level ground.
The transmission fluid level can be checked two
ways.
PROCEDURE ONE
(1) Transmission fluid must be at normal operat-
ing temperature for accurate fluid level check. Drive
vehicle if necessary to bring fluid temperature up to
normal hot operating temperature of 82ÉC (180ÉF).
(2) Position vehicle on level surface.
(3) Start and run engine at curb idle speed.
(4) Apply parking brakes.
(5) Shift transmission momentarily into all gear
ranges. Then shift transmission back to NEUTRAL.
(6) Clean top of filler tube and dipstick to keep
dirt from entering tube.
(7) Remove dipstick (Fig. 87) and check fluid level
as follows:
(a) Correct acceptable level is in crosshatch area.
(b) Correct maximum level is to MAX arrow
mark.
(c) Incorrect level is at or below MIN line.
(d) If fluid is low, add only enough MopartAT F
+4, type 9602, to restore correct level. Do not over-
fill.
21 - 70 AUTOMATIC TRANSMISSION - 42REWJ
FLUID AND FILTER (Continued)

TORQUE CONVERTER
DRAINBACK VALVE
DESCRIPTION
The drainback valve is located in the transmission
cooler outlet (pressure) line.
OPERATION
The valve prevents fluid from draining from the
converter into the cooler and lines when the vehicle
is shut down for lengthy periods. Production valves
have a hose nipple at one end, while the opposite end
is threaded for a flare fitting. All valves have an
arrow (or similar mark) to indicate direction of flow
through the valve.
STANDARD PROCEDURE - TORQUE
CONVERTER DRAINBACK VALVE
The converter drainback check valve is located in
the cooler outlet (pressure) line near the radiator
tank. The valve prevents fluid drainback when the
vehicle is parked for lengthy periods. The valve check
ball is spring loaded and has an opening pressure of
approximately 2 psi.
The valve is serviced as an assembly; it is not
repairable. Do not clean the valve if restricted, or
contaminated by sludge, or debris. If the valve fails,
or if a transmission malfunction occurs that gener-
ates significant amounts of sludge and/or clutch par-
ticles and metal shavings, the valve must be
replaced.
The valve must be removed whenever the cooler
and lines are reverse flushed. The valve can be flow
tested when necessary. The procedure is exactly the
same as for flow testing a cooler.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheating condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way flow
device. It must be properly oriented in terms of flow
direction for the cooler to function properly. The
valve must be installed in the pressure line. Other-
wise flow will be blocked and would cause an over-
heating condition and eventual transmission failure.
TRANSMISSION
TEMPERATURE SENSOR
DESCRIPTION
Transmission fluid temperature readings are sup-
plied to the transmission control module by the ther-
mistor (Fig. 254). The temperature readings are used
to control engagement of the fourth gear overdrive
clutch, the converter clutch, and governor pressure.
Normal resistance value for the thermistor at room
temperature is approximately 2000 ohms.
The thermistor is part of the governor pressure
sensor assembly and is immersed in transmission
fluid at all times.
OPERATION
The PCM prevents engagement of the converter
clutch and overdrive clutch, when fluid temperature
is below approximately 10ÉC (50ÉF).
If fluid temperature exceeds 126ÉC (260ÉF), the
PCM causes a 4-3 downshift and engage the con-
verter clutch. Engagement is according to the third
gear converter clutch engagement schedule.
The overdrive OFF lamp in the instrument panel
illuminates when the shift back to third occurs. The
transmission will not allow fourth gear operation
until fluid temperature decreases to approximately
110ÉC (230ÉF).
Fig. 254 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
21 - 134 AUTOMATIC TRANSMISSION - 42REWJ

(8) Engine starts must be possible with shifter
lever in PARK or NEUTRAL gate positions only.
Engine starts must not be possible in any other gate
positions other than PARK or NEUTRAL.
(9) With shifter lever handle push-button not
depressed and lever detent in:
²PARK position- apply forward force on center of
handle and remove pressure. Engine start must be
possible.
²PARK position- apply rearward force on center
of handle and remove pressure. Engine start must be
possible.
²NEUTRAL position- engine start must be possi-
ble.
²NEUTRAL position, engine running and brakes
applied- Apply forward force on center of shift han-
dle. Transmission should not be able to shift into
REVERSE detent.
FLUID AND FILTER
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
(1) Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
(2) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.(3) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to reverse flush cooler and lines after
repair
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary cool-
ers as well. The torque converter should also be
replaced whenever a failure generates sludge and
debris. This is necessary because normal converter
flushing procedures will not remove all contami-
nants.
21 - 228 AUTOMATIC TRANSMISSION - 545RFEWJ
BRAKE TRANSMISSION SHIFT INTERLOCK MECHANISM (Continued)

SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
BUCKET SEAT BACK FRAME RECLINER BOLTS TO SEAT CUSHION
FRAME28 20 Ð
BUCKET SEAT RECLINER TO SEAT BACK FRAME BOLTS 28 20 Ð
BUCKET SEAT TRACK ADJUSTER NUTS TO SEAT CUSHION FRAME 28 20 Ð
FRONT BUCKET SEAT TO FLOOR PAN BOLTS 40 30 Ð
FRONT BUCKET SEAT TO FLOOR PAN FRONT BOLTS 40 30 Ð
FRONT DOOR HINGE BOLTS 35 26 Ð
FRONT DOOR LATCH TO DOOR SCREWS 10 Ð 89
FRONT DOOR STRIKER TO B-PILLAR 28 20 Ð
HOOD LATCH TO RADIATOR CROSSMEMBER 11 8 Ð
LIFT GATE LATCH STRIKER TO D-PILLAR NUTS 10 Ð 89
REAR DOOR LATCH TO DOOR SCREWS 10 Ð 89
REAR DOOR STRIKER TO C-PILLAR SCREWS 28 20 Ð
REAR SEAT BACK LATCH/HINGE TO SEAT BACK FRAME 28 20 Ð
REAR SEAT BACK LEFT SIDE SUPPORT BRACKET TO CENTER PIVOT
BRACKET28 20 Ð
REAR SEAT BACK RIGHT SIDE SUPPORT BRACKET 28 20 Ð
REAR SEAT CUSHION LATCH BASE PANEL SCREWS 8 Ð 75
REAR SEAT CUSHION TO FLOOR PAN BOLTS 11 8 Ð
SUNROOF MODULE TO ROOF PANEL NUTS 11 8 Ð
SPECIAL TOOLS
BODY
Remover, Moldings C-4829
23 - 4 BODYWJ
BODY (Continued)

(6) Remove bolts attaching hinges to hood.
(7) With the aid of a helper, remove hood from
vehicle.
INSTALLATION
(1) Position hood on hinges.
(2) Install bolts finger-tight.
(3) Align hinges with installation reference marks
and tighten bolts.
(4) Install hood support prop rods.
(5) Connect underhood lamp connector.
(6) Inspect hood for proper alignment and adjust
as necessary.
ADJUSTMENTS
HOOD ADJUSTMENT
The hood attaching holes are enlarged to aid front,
back and side to side adjustment.
(1) If hood is low in relation to cowl panel, insert
shims between hinge and hood.
(2) Adjust hood bumper in or out to adjust hood-
to-fender height alignment.
(3) Adjust the hood latch as necessary. Tighten the
nuts to 11N´m (8 ft. lbs.).
(4) Align the latch striker so that striker enters
the latch squarely and without binding.
INSULATION
REMOVAL
(1) Raise the hood.
(2) Remove the insulation panel fasteners.
(3) Remove the hood insulation panel.
INSTALLATION
(1) Position the insulation panel on the underside
of the hood.
(2) Install the insulation panel fasteners.
(3) Close the hood.
LATCH
REMOVAL
(1) Remove nuts attaching latch to radiator cross-
member support (Fig. 2).
(2) Disconnect hood release cable from latch.
(3) Separate latch from vehicle.
INSTALLATION
(1) Connect latch release cable to latch.
(2) Position latch on radiator crossmember sup-
port.
(3) Install nuts attaching latch to radiator cross-
member support. Tighten nuts to 11 N´m (8 ft. lbs.)
torque (Fig. 2).
Fig. 2 Hood Latch
1 - HOOD RELEASE CABLE
2-LATCH
3 - BUMPER
23 - 34 HOODWJ
HOOD (Continued)

FRONT DOOR WEATHERSTRIP
REMOVAL
(1) Remove A-pillar trim (Refer to 23 - BODY/IN-
TERIOR/A-PILLAR TRIM - REMOVAL).
(2) Remove B-pillar upper trim (Refer to 23 -
BODY/INTERIOR/B-PILLAR UPPER TRIM -
REMOVAL).
(3) Remove B-pillar lower trim (Refer to 23 -
BODY/INTERIOR/B-PILLAR LOWER TRIM -
REMOVAL).
(4) Pull weatherstrip from door opening flange.
INSTALLATION
(1) Position weatherstrip at corners.
(2) Move upward and around edge of door opening
seating weatherstrip onto flange (Fig. 7).
(3) Engage connector plug with each end of weath-
erstrip at bottom of door opening.
(4) Install B-pillar lower trim (Refer to 23 - BODY/
INTERIOR/B-PILLAR LOWER TRIM - INSTALLA-
TION).
(5) Install B-pillar upper trim (Refer to 23 -
BODY/INTERIOR/B-PILLAR UPPER TRIM -
INSTALLATION).
(6) Install A-pillar trim (Refer to 23 - BODY/INTE-
RIOR/A-PILLAR TRIM - INSTALLATION).
HOOD SEAL
REMOVAL
(1) Raise hood.
(2) Pull hood seal from upper radiator crossmem-
ber.
(3) Separate seal from upper radiator crossmember
(Fig. 8).
INSTALLATION
(1) Position seal on upper radiator crossmember.
(2) Press seal onto upper radiator crossmember to
seat.
Fig. 7 Door Opening
1 - REAR DOOR OPENING WEATHERSTRIP
2 - FRONT DOOR OPENING WEATHERSTRIP
Fig. 8 Hood Seal
1 - HOOD SEAL
23 - 108 WEATHERSTRIP/SEALSWJ