Lamps JEEP GRAND CHEROKEE 2002 WJ / 2.G User Guide

INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer to
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter Kit
6987B on differential locating holes. Install hold
down clamps and tighten the tool turnbuckle finger-
tight.
(2) Install a Pilot Stud C-3288-B at the left side of
the differential housing. Attach Dial Indicator C-3339
to pilot stud. Load the indicator plunger against the
opposite side of the housing and zero the indicator.
(3) Spread the housing enough to install the case
in the housing. Measure the distance with the dial
indicator.
CAUTION: Never spread the housing over 0.50 mm
(0.020 in). If housing is over-spread, it could dis-
torted and damaged the housing.
(4) Remove the dial indicator.
(5) Install differential case in the housing (Fig.
46). Make sure the differential bearing cups remain
on the bearings and the preload shims remain
between the face of the bearing cup and housing. Tap
the differential case to ensure the bearings cups and
shims are fully seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing.
If differential is installed with the oil feed tube
pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install the bearing caps at their original loca-
tions (Fig. 47).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten the bearing cap bolts to 61 N´m (45 ft.
lbs.).
(10) Install the hub bearings and axle shafts.
Fig. 46 DIFFERENTIAL CASE REMOVAL
1 - DIFFERENTIAL HOUSING
2 - DIFFERENTIAL CASE
3 - BEARING CUPS
Fig. 47 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
WJFRONT AXLE - 186FBI 3 - 43
DIFFERENTIAL (Continued)

(7) Check rotating torque with an inch pound
torque wrench (Fig. 44). The rotating torque of the
pinion gear should be, the reading recorded during
removal plus an additional 0.56 N´m (5 in. lbs.).
(8) Install propeller shaft with reference marks
align.
(9) Install rear brake calipers and rotors (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/ROTORS
- INSTALLATION).
(10) Add gear lubricant, if necessary.
(11) Install wheel and tire assemblies.
(12) Remove supports and lower vehicle.
DIFFERENTIAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove fill hole plug from the differential
housing cover.
(3) Remove differential housing cover and drain
fluid.
(4) Clean the housing cavity with flushing oil, light
engine oil or lint free cloth.
NOTE: Do not use water, steam, kerosene or gaso-
line for cleaning.
(5) Remove axle shafts.(6)
Note the reference letters stamped on the bearing
caps and housing machined sealing surface (Fig. 45).
(7) Loosen the differential bearing cap bolts.
(8) Position Spreader W-129-B with Adapter Kit
6987B on differential locating holes (Fig. 46). Install
holddown clamps and tighten the turnbuckle finger-
tight.
Fig. 44 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE
Fig. 45 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 46 SPREADER LOCATION
1 - DIFFERENTIAL HOUSING
2 - DOWEL
3 - SAFETY HOLD DOWN
4 - SPREADER
5 - TURNBUCKLE
WJREAR AXLE - 198RBI 3 - 75
COLLAPSIBLE SPACER (Continued)

DISASSEMBLY
(1) Remove pinion shaft lock screw (Fig. 50).
(2) Remove pinion shaft.
(3) Rotate differential side gears and remove dif-
ferential pinions and thrust washers (Fig. 51).
(4) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install differential pinion gears and thrust
washers.
(3) Install the pinion mate shaft.
(4) Align hole in the pinion mate shaft with the
hole in the differential case and install the pinion
mate shaft lock screw.
(5) Lubricate all differential components with
hypoid gear lubricant.
INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter set
6987 on differential housing locating holes. Install
the holddown clamps and tighten the tool turnbuckle
finger-tight.
(2) Install a Pilot Stud C-3288-B at the left side of
the differential housing. Attach Dial Indicator C-3339
to pilot stud. Load the indicator plunger against the
opposite side of the housing and zero the indicator.
CAUTION: Never spread the housing over 0.38 mm
(0.015 in). If housing is over-spread, it could be dis-
torted or damaged.
(3) Spread housing enough to install the case in
the housing.
(4) Remove the dial indicator.
(5) Install differential case in housing (Fig. 52).
Verify differential bearing cups remain in position on
the bearings and preload shims are between the face
of the bearing cup and the housing. Tap the differen-
tial case to ensure bearings cups and shims are
seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing
(Fig. 53). If differential is installed with the oil feed
tube pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install bearing caps in their original locations
(Fig. 54).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten bearing cap bolts in a criss-cross pat-
tern to 77 N´m (57 ft. lbs.).
(10) Install the axle shafts.
Fig. 50 SHAFT LOCK SCREW
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 51 DIFFERENTIAL GEARS
1 - THRUST WASHER
2 - SIDE GEAR
3 - DIFFERENTIAL PINION
WJREAR AXLE - 198RBI 3 - 77
DIFFERENTIAL (Continued)

NOTE: If more than 380 N´m (280 ft. lbs.) torque is
required to crush the collapsible spacer, the spacer
is defective and must be replaced.
(7) Check rotating torque with an inch pound
torque wrench (Fig. 44). The rotating torque of the
pinion gear should be, the reading recorded during
removal plus an additional 0.56 N´m (5 in. lbs.).
(8)
Install propeller shaft with reference marks align.
(9) Install rear brake rotors and calipers.
(10) Add gear lubricant, if necessary.
(11) Install wheel and tire assemblies.
(12) Remove supports and lower vehicle.
DIFFERENTIAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove fill hole plug from the differential
housing cover.
(3) Remove differential housing cover and drain
fluid.
(4) Clean the housing cavity with flushing oil, light
engine oil or lint free cloth.
NOTE: Do not use water, steam, kerosene or gaso-
line for cleaning.
(5) Remove axle shafts.(6)
Note the reference letters stamped on the bearing
caps and housing machined sealing surface (Fig. 45).
(7) Loosen the differential bearing cap bolts.
(8) Position Spreader W-129-B with Adapter Kit
6987B on differential locating holes (Fig. 46). Install
holddown clamps and tighten the turnbuckle finger-
tight.
Fig. 44 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE
Fig. 45 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 46 SPREADER LOCATION
1 - DIFFERENTIAL HOUSING
2 - DOWEL
3 - SAFETY HOLD DOWN
4 - SPREADER
5 - TURNBUCKLE
WJREAR AXLE - 226RBA 3 - 115
COLLAPSIBLE SPACER (Continued)

DISASSEMBLY
(1) Remove pinion shaft lock screw (Fig. 50).
(2) Remove pinion shaft.
(3) Rotate differential side gears and remove dif-
ferential pinions and thrust washers (Fig. 51).
(4) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install differential pinion gears and thrust
washers.
(3) Install the pinion mate shaft.
(4) Align hole in the pinion mate shaft with the
hole in the differential case and install the pinion
mate shaft lock screw.
(5) Lubricate all differential components with
hypoid gear lubricant.
INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter set
6987 on differential housing locating holes. Install
the holddown clamps and tighten the tool turnbuckle
finger-tight.
(2) Install a Pilot Stud C-3288-B at the left side of
the differential housing. Attach Dial Indicator C-3339
to pilot stud. Load the indicator plunger against the
opposite side of the housing and zero the indicator.
CAUTION: Never spread the housing over 0.38 mm
(0.015 in). If housing is over-spread, it could be dis-
torted or damaged.
(3) Spread housing enough to install the case in
the housing.
(4) Remove the dial indicator.
(5) Install differential case in housing (Fig. 52).
Verify differential bearing cups remain in position on
the bearings and preload shims are between the face
of the bearing cup and the housing. Tap the differen-
tial case to ensure bearings cups and shims are
seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing
(Fig. 53). If differential is installed with the oil feed
tube pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install bearing caps in their original locations
(Fig. 54).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten bearing cap bolts in a criss-cross pat-
tern to 77 N´m (57 ft. lbs.).
(10) Install the axle shafts.
Fig. 50 SHAFT LOCK SCREW
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 51 DIFFERENTIAL GEARS
1 - THRUST WASHER
2 - SIDE GEAR
3 - DIFFERENTIAL PINION
WJREAR AXLE - 226RBA 3 - 117
DIFFERENTIAL (Continued)

ELECTRIC BRAKE
DESCRIPTION
The electronic brake distribution (EBD) functions
like a rear proportioning valve. The EBD system uses
the ABS system to control the slip of the rear wheels
in partial braking range. The braking force of the
rear wheels is controlled electronically by using the
inlet and outlet valves located in the HCU.
OPERATION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
HCU resulting in a drop in fluid pressure to the rear
brakes. In order to increase the rear brake pressure
the outlet valve is switched off and the inlet valve is
pulsed. This increases the pressure to the rear
brakes. This will continue until the required slip dif-
ference is obtained. At the end of EBD braking (no
brake application) the fluid in the LPA drains back to
the master cylinder by switching on the outlet valve
and draining through the inlet valve check valve. At
the same time the inlet valve is switched on to pre-
vent a hydraulic short circiut in case of another
brake application.
The EBD will remain functional during many ABS
fault modes. If the red and amber warning lamps are
illuminated the EBD may have a fault.
FRONT WHEEL SPEED
SENSOR
DESCRIPTION
A wheel speed sensor is used at each wheel. The
front sensors are mounted to the steering knuckles.
The rear sensors are mounted at the outboard end of
the axle. Tone wheels are mounted to the outboard
ends of the front and rear axle shafts. The gear type
tone wheel serves as the trigger mechanism for each
sensor.
OPERATION
The sensors convert wheel speed into a small digi-
tal signal. The CAB sends 12 volts to the sensors.
The sensor has an internal magneto resistance
bridge that alters the voltage and amperage of the
signal circuit. This voltage and amperage is changed
by magnetic induction when the toothed tone wheel
passes the wheel speed sensor. This digital signal issent to the CAB. The CAB measures the voltage and
amperage of the digital signal for each wheel.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the front wheel sensor mounting bolt
(Fig. 1).
(3) Remove the sensor from the steering knuckle.
(4) Disengage the sensor wire from the brackets
(Fig. 1)on the steering knuckle.
(5) Disconnect the sensor from the sensor harness
(Fig. 2)and (Fig. 3).
(6) Remove the sensor and wire.
INSTALLATION
(1) Install the sensor on the steering knuckle.
(2) Apply Mopar Lock N' Seal or Loctitet242 to
the sensor mounting bolt. Use new sensor bolt if orig-
inal bolt is worn or damaged.
(3) Install the sensor mounting bolt and tighten
bolt to 12-14 N´m (106-124 in. lbs.).
(4) Engage the grommets on the sensor wire to the
steering knuckle brackets.
(5) Connect the sensor wire to the harness connec-
tor.
(6) Check the sensor wire routing. Be sure the
wire is clear of all chassis components and is not
twisted or kinked at any spot.
(7) Remove the support and lower vehicle.
Fig. 1 Sensor Location
1 - BRACKET
2 - BRACKET
3 - WHEEL SPEED SENSOR
4 - MOUNTING BOLT
WJBRAKES - ABS 5 - 43

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM 4.7L
ENGINE..............................1
DESCRIPTION - COOLING SYSTEM
ROUTING 4.7L ENGINE..................1
DESCRIPTIONÐCOOLING SYSTEM 4.0L
ENGINE..............................1
DESCRIPTIONÐCOOLING SYSTEM
ROUTING 4.0L ENGINE..................1
DESCRIPTIONÐHOSE CLAMPS...........1
OPERATION
OPERATIONÐCOOLING SYSTEM.........2
OPERATIONÐHOSE CLAMPS............2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)...................3
DIAGNOSIS AND TESTINGÐPRELIMINARY
CHECKS.............................3
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIAGNOSIS CHART.............5
DIAGNOSIS AND TESTING - COOLING
SYSTEM LEAKS......................10DIAGNOSIS AND TESTING - COOLING
SYSTEM DEAERATION.................12
STANDARD PROCEDURE
STANDARD PROCEDUREÐDRAINING
COOLING SYSTEM 4.7L ENGINE.........12
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 4.7L ENGINE.........12
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM - 4.0L ENGINE........13
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM - 4.0L ENGINE........13
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................13
STANDARD PROCEDURE - COOLING
SYSTEM - REVERSE FLUSHING..........14
SPECIFICATIONS
TORQUE............................14
SPECIAL TOOLS
COOLING...........................15
ACCESSORY DRIVE......................16
ENGINE...............................24
TRANSMISSION.........................55
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM 4.7L
ENGINE
The cooling system consists of the following items:
²Hydraulic cooling fan and fan drive assembly
²Radiator
²Power steering oil cooler
²Radiator pressure cap
²Thermostat
²Coolant reserve/overflow system
²Transmission oil cooler (if equipped with an
automatic transmission)
²Coolant
²Water pump
²Hoses and hose clamps
DESCRIPTION - COOLING SYSTEM ROUTING
4.7L ENGINE
For cooling system routing refer to (Fig. 1).
DESCRIPTIONÐCOOLING SYSTEM 4.0L
ENGINE
The cooling system consists of:
²A radiator
²Mechanical Cooling Fan
²Thermal viscous fan drive-Low disengaged
²Fan shroud (Fig. 2)
²Radiator pressure cap
²Thermostat
²Coolant reserve/overflow system
²Transmission oil cooler (if equipped with an
automatic transmission)
²Coolant
²Water pump
²Hoses and hose clamps
²Accessory drive belt
DESCRIPTIONÐCOOLING SYSTEM ROUTING
4.0L ENGINE
For cooling system routing refer to (Fig. 3).
DESCRIPTIONÐHOSE CLAMPS
The cooling system utilizes both worm drive and
spring type hose clamps. If a spring type clamp
WJCOOLING 7 - 1

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).
OPERATION
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 alsomaintains 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.
OPERATIONÐHOSE CLAMPS
The worm type hose clamp uses a specified torque
value to maintain proper tension on a hose connec-
tion.
Fig. 1 Engine Cooling System 4.7L Engine
1 - LH CYL. HEAD
2 - AIR BLEED
3 - THERMOSTAT LOCATION
4 - RH CYL. HEAD5 - RH BANK CYL. BLOCK
6 - LH BANK CYL. BLOCK
7 - COOLANT TEMP. SENSOR
7 - 2 COOLINGWJ
COOLING (Continued)

REMOVAL
REMOVALÐ4.0L ENGINE
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
(1) Drain the coolant from the radiator until the
level is below the thermostat housing (Refer to 7 -
COOLING - 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, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 52). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING 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 matching number or letter.
(2) Remove radiator upper hose and heater hose at
thermostat housing.
(3) Disconnect wiring connector at engine coolant
temperature sensor.
(4) Remove thermostat housing mounting bolts,
thermostat housing, gasket and thermostat (Fig. 24).
Discard old gasket.
(5) Clean the gasket mating surfaces.
REMOVALÐ4.7L ENGINE
WARNING: DO NOT LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND PRESSURIZED.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
If thermostat is being replaced, be sure that
replacement is specified thermostat for vehicle model
and engine type.
(1) Disconnect negative battery cable at battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Raise vehicle on hoist.
(4) Remove splash shield.(5) Remove lower radiator hose clamp and lower
radiator hose at thermostat housing.
(6) Remove thermostat housing mounting bolts,
thermostat housing and thermostat (Fig. 25).
INSTALLATION
INSTALLATIONÐ4.0L ENGINE
(1) Install the replacement thermostat so that the
pellet, which is encircled by a coil spring, faces the
engine. All thermostats are marked on the outer
flange to indicate the proper installed position.
(a) Observe the recess groove in the engine cyl-
inder head (Fig. 26).
(b) Position thermostat in groove with arrow and
air bleed hole on outer flange pointing up.
(2) Install replacement gasket and thermostat
housing.
CAUTION: Tightening the thermostat housing
unevenly or with the thermostat out of its recess,
may result in a cracked housing.
(3) Tighten the housing bolts to 22 N´m (16 ft. lbs.)
torque.
(4) Install hoses to thermostat housing.
Fig. 24 Thermostat
1 - LONG BOLT
2 - GASKET
3 - THERMOSTAT
4 - THERMOSTAT HOUSING
5 - SHORT BOLT
7 - 38 ENGINEWJ
ENGINE COOLANT THERMOSTAT (Continued)

INSTALLATION
(1) Position relay to body and install 2 bolts.
Tighten bolts to 3 N´m (25 in. lbs.) torque.
(2) Connect electrical connector to relay.
(3) Connect vacuum hose to reservoir.
(4) Install reservoir and tighten 2 bolts to 3 N´m
(25 in. lbs.) torque.
(5) Install front bumper and grill assembly.
RADIATOR - 4.7L
DESCRIPTION
All vehicles are equipped with a cross flow type
radiator with plastic side tanks (Fig. 31).
Plastic tanks, while stronger than brass, are sub-
ject to damage by impact, such as from tools or
wrenches. Handle radiator with care.
REMOVAL
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR. REFER TO COOLING SYSTEM DRAIN-
ING.Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
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, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 32). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 33). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
CAUTION: When removing the radiator or A/C con-
denser for any reason, note the location of all radi-
ator-to-body and radiator-to-A/C condenser rubber
air seals (Fig. 34). These are used at the top, bot-
tom and sides of the radiator and A/C condenser.
To prevent overheating, these seals must be
installed to their original positions.
(1) Disconnect the negative battery cable at bat-
tery.
(2) Drain coolant from radiator (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(3) Remove the front grill (Refer to 23 - BODY/EX-
TERIOR/GRILLE - REMOVAL).
Fig. 30 Radiator Cooling Fan Relay Removal/
Installation
1 - ELECTRICAL CONNECTOR
2 - RADIATOR FAN RELAY
3 - MOUNTING BOLTS (2)
Fig. 31 Cross Flow Radiator - Typical
1 - RADIATOR
7 - 42 ENGINEWJ
PWM FAN CONTROL MODULE - 4.0L (Continued)