EGR JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 6).
DESCRIPTION
A multi-purpose, hypoid gear lubricant which con-
forms to MIL-L-2105C and API GL 5 quality specifi-
cations should be used. Mopar Hypoid Gear
Lubricant conforms to these specifications.
FRONT AXLE
²Lubricant is SAE 75W-140 SYNTHETIC.
REAR AXLE
²Lubricant is a thermally stable SAE 80W-90
gear lubricant.
²Lubricant for heavy-duty or trailer tow use is
SAE 75W-140 SYNTHETIC.
NOTE: Trac-lokTand Vari-lokTequipped axles
require a friction modifier be added to the lubricant.
DESCRIPTION - TRANSFER CASE - NV242
Recommended lubricant for the NV242 transfer
case is MopartATF+4, type 9602 Automatic Trans-
mission Fluid.
DESCRIPTION - TRANSFER CASE - NV247
MopartTransfer Case Lubricant (P/N 05016796) is
the only lubricant recommended for the NV247
transfer case.
DESCRIPTION - AUTOMATIC TRANSMISSION
FLUID
NOTE: Refer to Service Procedures in this group for
fluid level checking procedures.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid is the recommended fluid for
DaimlerChrysler automatic transmissions.
Dexron II fluid IS NOT recommended. Clutch
chatter can result from the use of improper
fluid.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid when new is red in color. The ATF is dyed
red so it can be identified from other fluids used in
the vehicle such as engine oil or antifreeze. The red
color is not permanent and is not an indicator of fluid
condition. As the vehicle is driven, the ATF will begin
to look darker in color and may eventually become
brown.This is normal.ATF+4 also has a unique
odor that may change with age. Consequently, odor
and color cannot be used to indicate the fluid condi-
tion or the need for a fluid change.
FLUID ADDITIVES
DaimlerChrysler strongly recommends against the
addition of any fluids to the transmission, other than
those automatic transmission fluids listed above.
Exceptions to this policy are the use of special dyes
to aid in detecting fluid leaks.
Various ªspecialº additives and supplements exist
that claim to improve shift feel and/or quality. These
additives and others also claim to improve converter
clutch operation and inhibit overheating, oxidation,
varnish, and sludge. These claims have not been sup-
ported to the satisfaction of DaimlerChrysler and
these additivesmust not be used.The use of trans-
mission ªsealersº should also be avoided, since they
may adversely affect the integrity of transmission
seals.
Fig. 5 Temperature/Engine Oil Viscosity - 4.0L
Fig. 6 API Symbol
WJLUBRICATION & MAINTENANCE 0 - 5
FLUID TYPES (Continued)

WHEEL ALIGNMENT
TABLE OF CONTENTS
page page
WHEEL ALIGNMENT
DESCRIPTION..........................3
OPERATION............................3
STANDARD PROCEDURE
STANDARD PROCEDURE - CAMBER.......3STANDARD PROCEDURE - CASTER.......4
STANDARD PROCEDURE - TOE POSITION . . 4
SPECIFICATIONS
ALIGNMENT..........................5
WHEEL ALIGNMENT
DESCRIPTION
Wheel alignment involves the correct positioning of
the wheels in relation to the vehicle. The positioning
is accomplished through suspension and steering
linkage adjustments. An alignment is considered
essential for efficient steering, good directional stabil-
ity and to minimize tire wear. The most important
measurements of an alignment are caster, camber
and toe position (Fig. 1).
CAUTION: Never attempt to modify suspension or
steering components by heating or bending.
CAUTION: Components attached with a nut and cot-
ter pin must be torqued to specification. Then if the
slot in the nut does not line up with the cotter pin
hole, tighten nut until it is aligned. Never loosen the
nut to align the cotter pin hole.
NOTE: Periodic lubrication of the front suspension/
steering system components may be required. Rub-
ber bushings must never be lubricated, Refer to
Lubrication And Maintenance for the recommended
maintenance schedule.
OPERATION
²CASTERis the forward or rearward tilt of the
steering knuckle from vertical. Tilting the top of the
knuckle rearward provides positive caster. Tilting the
top of the knuckle forward provides negative caster.
Caster is a directional stability angle. This angle
enables the front wheels to return to a straight
ahead position after turns (Fig. 1).
²CAMBERis the inward or outward tilt of the
wheel relative to the center of the vehicle. Tilting the
top of the wheel inward provides negative camber.
Tilting the top of the wheel outward provides positive
camber. Incorrect camber will cause wear on theinside or outside edge of the tire. The angle is not
adjustable, damaged component(s) must be replaced
to correct the camber angle (Fig. 1).
²WHEEL TOE POSITIONis the difference
between the leading inside edges and trailing inside
edges of the front tires. Incorrect wheel toe position
is the most common cause of unstable steering and
uneven tire wear. The wheel toe position is thefinal
front wheel alignment adjustment (Fig. 1).
²STEERING AXIS INCLINATION ANGLEis
measured in degrees and is the angle that the steer-
ing knuckles are tilted. The inclination angle has a
fixed relationship with the camber angle. It will not
change except when a spindle or ball stud is dam-
aged or bent. The angle is not adjustable, damaged
component(s) must be replaced to correct the steering
axis inclination angle.
²THRUST ANGLEis the angle of the rear axle
relative to the centerline of the vehicle. Incorrect
thrust angle can cause off-center steering and exces-
sive tire wear. This angle is not adjustable, damaged
component(s) must be replaced to correct the thrust
angle (Fig. 1).
STANDARD PROCEDURE
STANDARD PROCEDURE - CAMBER
Before each alignment reading the vehicle should
be jounced (rear first, then front). Grasp each
bumper at the center and jounce the vehicle up and
down three times. Always release the bumper in the
down position.
To obtain an accurate alignment, a 4 wheel align-
ment machine must be used and the equipment cali-
bration verified.
The wheel camber angle is preset. This angle is not
adjustable and cannot be altered.
WJWHEEL ALIGNMENT 2 - 3

NOTE: Make sure the toe setting does not change
during clamp tightening.
(6) Verify alignment specifications, then turn the
engine off.
STEERING WHEEL CENTERING
NOTE: The steering wheel can be centered without
affecting the toe position.
(1) Loosen the drag link adjustment sleeve clamp
bolts.
(2) Turn the adjustment sleeve to center the
wheel.
(3) Position the clamp bolts as shown (Fig. 2)for
proper clearance.
(4) Tighten the clamp bolts to 68 N´m (50 ft. lbs.).
(5) Road test the vehicle to verify the wheel is cen-
tered.
SPECIFICATIONS
ALIGNMENT
NOTE: Specifications are in degrees.
FRONT WHEELS - STANDARD SUSPENSION
SPECIFICATIONS
DESCRIPTION SPECIFICATION
PREFERRED CASTER
+ 6.75ÉCAMBER
20.37ÉTOTAL
TOE-IN
+ 0.20É
RANGE + 6.0É to
+ 7.5É20.75É
to + 0.5É+ .14É to
+ .26É
MAX RT/LT
DIFFERENCE0.5É 0.5É 0.5É
FRONT WHEELS - UP-COUNTRY SUSPENSION
SPECIFICATIONS
DESCRIPTION SPECIFICATION
PREFERRED CASTER
+ 6.5ÉCAMBER
20.37ÉTOTAL
TOE-IN
+ 0.20É
RANGE + 5.7É to
+ 7.2É20.75É
to+0É+ 0.0É to
+ .36É
MAX RT/LT
DIFFERENCE0.5É 0.5É 0.06É
REAR AXLE
SPECIFICATIONS
DESCRIPTION SPECIFICATION
PREFERRED CAMBER
±.37ÉTHRUST
ANGLE
0ÉTOTAL
TOE-IN
+.37É
RANGE 0É to
±.75É  0.25É 0É to
+.70É
Fig. 2 Steering Linkage
1 - DRAG LINK ADJUSTMENT SLEEVE
2 - TIE ROD ADJUSTMENT SLEEVE
WJWHEEL ALIGNMENT 2 - 5
WHEEL ALIGNMENT (Continued)

(3) Rotate the shaft until transmission/transfer
case output yoke bearing cap is facing downward, if
necessary.
NOTE: Always make measurements from front to rear.
(4)Place Inclinometer on yoke bearing cap, or the
pinion flange ring, (A) parallel to the shaft (Fig. 4). Cen-
ter bubble in sight glass and record measurement.
NOTE: This measurement will give you the trans-
mission or Output Yoke Angle (A).
(5) Rotate propeller shaft 90 degrees and place
Inclinometer on yoke bearing cap, or propeller shaft
tube on C/V propeller shaft, parallel to the shaft (Fig.
5). Center bubble in sight glass and record measure-
ment. This measurement can also be taken at the
rear end of the shaft.
NOTE: This measurement will give you the propeller
shaft angle (C).
(6) Subtract smaller figure from larger (C minus
A) to obtain transmission output operating angle.
(7) Rotate propeller shaft 90 degrees and place
Inclinometer on pinion yoke bearing cap parallel to
the shaft (Fig. 6). Center bubble in sight glass and
record measurement.
NOTE: This measurement will give you the pinion
shaft or input yoke angle (B).
(8) Subtract smaller figure from larger (C minus
B) to obtain axle Input Operating Angle.Refer to rules given below and the example in (Fig.
7) for additional information.
²Good cancellation of U-joint operating angles
(within 1É).
²Operating angles less than 3É.
²Operating angles less than 10É for double cardan
U-joint.
²At least 1/2 of one degree continuous operating
(propeller shaft) angle.
Fig. 4 OUTPUT YOKE ANGLE (A)
1 - SLIP YOKE BEARING CAP
2 - INCLINOMETER
Fig. 5 PROPELLER SHAFT ANGLE (C)
1 - SHAFT YOKE BEARING CAP
2 - INCLINOMETER
Fig. 6 INPUT YOKE ANGLE (B)
1 - PINION YOKE BEARING CAP
2 - INCLINOMETER
3 - 4 PROPELLER SHAFTWJ
PROPELLER SHAFT (Continued)

(33) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(34) Zero dial indicator face to pointer.
(35) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.12 mm (0.005 in.) and
0.20 mm (0.008 in.). If backlash is not within specifi-
cations transfer the necessary amount of shim thick-
ness from one side of the housing to the other (Fig.
20).
(36) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at eight
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings vary
more than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform
Gear Contact Pattern Analysis procedure.
GEAR CONTACT PATTERN
The ring gear and pinion teeth contact patterns
will show if the pinion depth is correct in the hous-
ing. It will also show if the ring gear backlash has
been adjusted correctly. The backlash can be adjusted
within specifications to achieve desired tooth contact
patterns.
(1) Apply a thin coat of hydrated ferric oxide or
equivalent to the drive and coast side of the ring gear
teeth.
(2) Wrap, twist and hold a shop towel around the
pinion yoke to increase the turning resistance of the
pinion. This will provide a more distinct contact pat-
tern.
(3) With a boxed end wrench on a ring gear bolt,
rotate the differential case one complete revolution inboth directions while a load is being applied from
shop towel.
The areas on the ring gear teeth with the greatest
degree of contact against the pinion teeth will squee-
gee the compound to the areas with the least amount
of contact. Note and compare patterns on the ring
gear teeth to Gear Tooth Contact Patterns chart (Fig.
21)and adjust pinion depth and gear backlash as nec-
essary.
Fig. 20 BACKLASH SHIM ADJUSTMENT
3 - 28 FRONT AXLE - 186FBIWJ
FRONT AXLE - 186FBI (Continued)

GEAR CONTACT PATTERN
The ring gear and pinion teeth contact patterns
will show if the pinion depth is correct in the hous-
ing. It will also show if the ring gear backlash has
been adjusted correctly. The backlash can be adjusted
within specifications to achieve desired tooth contact
patterns.
(1) Apply a thin coat of hydrated ferric oxide or
equivalent to the drive and coast side of the ring gear
teeth.
(2) Wrap, twist and hold a shop towel around the
pinion yoke to increase the turning resistance of the
pinion. This will provide a more distinct contact pat-
tern.
(3) With a boxed end wrench on a ring gear bolt,
rotate the differential case one complete revolution in
both directions while a load is being applied from
shop towel.
The areas on the ring gear teeth with the greatest
degree of contact against the pinion teeth will squee-
gee the compound to the areas with the least amount
of contact. Note and compare patterns on the ring
gear teeth to Gear Tooth Contact Patterns chart (Fig.
24) and adjust pinion depth and gear backlash as
necessary.
Fig. 23 BACKLASH SHIM
WJREAR AXLE - 198RBI 3 - 63
REAR AXLE - 198RBI (Continued)

(32) Position the indicator plunger against a ring
gear tooth (Fig. 22).
(33) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(34) Zero dial indicator face to pointer.
(35) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.076 mm (0.003 in.) and
0.15 mm (0.006 in.). If backlash is not within specifi-
cations transfer the necessary amount of shim thick-
ness from one side of the housing to the other (Fig.
23).
(36) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at eight
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings vary
more than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform
Gear Contact Pattern procedure.
GEAR CONTACT PATTERN
The ring gear and pinion teeth contact patterns
will show if the pinion depth is correct in the axle
housing. It will also show if the ring gear backlashhas been adjusted correctly. The backlash can be
adjusted within specifications to achieve desired
tooth contact patterns.
(1) Apply a thin coat of hydrated ferric oxide or
equivalent to the drive and coast side of the ring gear
teeth.
(2) Wrap, twist and hold a shop towel around the
pinion yoke to increase the turning resistance of the
pinion. This will provide a more distinct contact pat-
tern.
(3) With a boxed end wrench on a ring gear bolt,
rotate the differential case one complete revolution in
both directions while a load is being applied from
shop towel.
The areas on the ring gear teeth with the greatest
degree of contact against the pinion teeth will squee-
gee the compound to the areas with the least amount
of contact. Note and compare patterns on the ring
gear teeth to Gear Tooth Contact Patterns chart (Fig.
24) and adjust pinion depth and gear backlash as
necessary.
Fig. 22 RING GEAR BACKLASH
1 - DIAL INDICATOR
Fig. 23 BACKLASH SHIM
WJREAR AXLE - 226RBA 3 - 103
REAR AXLE - 226RBA (Continued)

INSTALLATION
INSTALLATION - FRONT DISC BRAKE ROTOR
NOTE: If a new rotor is installed it must be match
mounted to the hub/bearing.
(1) Install rotor on hub studs in its original loca-
tion.
(2) Install the caliper anchor assembly on the
knuckle. Install anchor bolts and tighten to 90-115
N´m (66-85 ft. lbs.).
(3) Install wheel and tire assembly.
(4) Remove support and lower the vehicle.
(5) Pump brake pedal to seat caliper pistons and
brake shoes. Do not move vehicle until firm brake
pedal is obtained.
INSTALLATION - REAR DISC BRAKE ROTOR
(1) Install rotor on axle studs.
(2) Install the caliper anchor assembly.
(3) Install anchor bolts and tighten to 90-115 N´m
(66-85 ft. lbs.).
(4) Install wheel and tire assembly.
(5) Remove support and lower the vehicle.
(6) Pump brake pedal until caliper pistons and
brake shoes are seated.
PARKING BRAKE
OPERATION
The parking brakes operated by a automatic ten-
sioner mechanism built into the hand lever and cable
system. The front cable is connected to the hand
lever and the equalizer. The rear cables attached to
the equalizer and the parking brake shoe actuator.
A set of drum type brake shoes are used for park-
ing brakes. The shoes are mounted to the rear disc
brake adaptor. The parking brake drum is integrated
into the rear disc brake rotor.
Parking brake cable adjustment is controlled by an
automatic tensioner mechanism. The only adjust-
ment if necessary is to the park brake shoes if the
linings are worn.
DIAGNOSIS AND TESTING - PARKING BRAKE
NOTE: Parking brake adjustment is controlled by an
automatic cable tensioner and does not require
adjustment. The only adjustment that may be nec-
essary would be to the park brake shoes if they are
worn.
The parking brake switch is in circuit with the red
warning lamp in the dash. The switch will cause the
lamp to illuminate only when the parking brakes are
applied. If the lamp remains on after parking brake
release, the switch or wires are faulty.
If the red lamp comes on a fault has occurred in
the front or rear brake hydraulic system.
If the red warning lamp and yellow warning lamp
come on, the electronic brake distribution may be at
fault.
In most cases, the actual cause of an improperly
functioning parking brake (too loose/too tight/won't
hold), can be traced to a parking brake component.
NOTE: The leading cause of improper parking brake
operation, is excessive clearance between the park-
ing brake shoes and the shoe braking surface.
Excessive clearance is a result of lining and/or
drum wear, drum surface machined oversize.
Excessive parking brake lever travel (sometimes
described as a loose lever or too loose condition), is
the result of worn brake shoes, improper brake shoe
adjustment, or improperly assembled brake parts.
A too loose condition can also be caused by inoper-
ative or improperly assembled parking brake shoe
parts.
A condition where the parking brakes do not hold,
will most probably be due to a wheel brake compo-
nent.
Items to look for when diagnosing a parking brake
problem, are:
²Brake shoe wear
²Drum surface (in rear rotor) machined oversize
²Front cable not secured to lever
²Rear cable not attached to actuator
²Rear cable seized
²Parking brake lever not seated
²Parking brake lever bind
5 - 34 BRAKES - BASEWJ
ROTORS (Continued)

BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION.........................41
OPERATION...........................41
DIAGNOSIS AND TESTING - ANTILOCK
BRAKES............................42
STANDARD PROCEDURE - BLEEDING ABS
BRAKE SYSTEM......................42
SPECIFICATIONS
TORQUE CHART......................42
ELECTRIC BRAKE
DESCRIPTION.........................43
OPERATION...........................43
FRONT WHEEL SPEED SENSOR
DESCRIPTION.........................43
OPERATION...........................43
REMOVAL.............................43INSTALLATION.........................43
G-SWITCH
DESCRIPTION.........................44
OPERATION...........................44
REMOVAL.............................44
INSTALLATION.........................44
REAR WHEEL SPEED SENSOR
DESCRIPTION.........................45
OPERATION...........................45
REMOVAL.............................45
INSTALLATION.........................46
HCU (HYDRAULIC CONTROL UNIT)
DESCRIPTION.........................46
OPERATION...........................46
REMOVAL.............................47
INSTALLATION.........................47
BRAKES - ABS
DESCRIPTION
The purpose of the antilock system is to prevent
wheel lockup during periods of high wheel slip. Pre-
venting lockup helps maintain vehicle braking action
and steering control.
The hydraulic system is a three channel design.
The front brakes are controlled individually and the
rear brakes in tandem.
The ABS electrical system is separate from other
vehicle electrical circuits. A separate controller oper-
ates the system.
OPERATION
The antilock CAB activates the system whenever
sensor signals indicate periods of high wheel slip.
High wheel slip can be described as the point where
wheel rotation begins approaching 20 to 30 percent of
actual vehicle speed during braking. Periods of high
wheel slip occur when brake stops involve high pedal
pressure and rate of vehicle deceleration.
Battery voltage is supplied to the CAB ignition ter-
minal when the ignition switch is turned to Run posi-
tion. The CAB performs a system initialization
procedure at this point. Initialization consists of a
static and dynamic self check of system electrical
components.
The static check occurs after the ignition switch is
turned to Run position. The dynamic check occurs
when vehicle road speed reaches approximately 30kph (18 mph). During the dynamic check, the CAB
briefly cycles the pump and solenoids to verify oper-
ation.
If an ABS component exhibits a fault during ini-
tialization, the CAB illuminates the amber warning
light and registers a fault code in the microprocessor
memory.
ANTILOCK BRAKING
The antilock system prevents lockup during high
slip conditions by modulating fluid apply pressure to
the wheel brake units.
Brake fluid apply pressure is modulated according
to wheel speed, degree of slip and rate of decelera-
tion. A sensor at each wheel converts wheel speed
into electrical signals. These signals are transmitted
to the CAB for processing and determination of
wheel slip and deceleration rate.
The ABS system has three fluid pressure control
channels. The front brakes are controlled separately
and the rear brakes in tandem. A speed sensor input
signal indicating a high slip condition activates the
CAB antilock program.
Two solenoid valves are used in each antilock con-
trol channel. The valves are all located within the
HCU valve body and work in pairs to either increase,
hold, or decrease apply pressure as needed in the
individual control channels.
The solenoid valves are not static during antilock
braking. They are cycled continuously to modulate
pressure. Solenoid cycle time in antilock mode can be
measured in milliseconds.
WJBRAKES - ABS 5 - 41

(1) Position sensor into the coolant recovery pres-
sure container (Fig. 1).
(2) Connect the coolant level sensor electrical con-
nector (Fig. 2).
(3) Close hood.
COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/ad-
justing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover
minor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
The coolant reservoir/overflow system has a radia-
tor mounted pressurized cap, an overflow tube and a
plastic coolant reservoir/overflow tank (Fig. 3)
mounted to the right inner fender.
RADIATOR FAN - 4.7L
DESCRIPTION
The hydraulic fan (Fig. 4) used on vehicles
equipped the 4.7L engine, replaces both the electric
fan and the engine driven mechanical fan. The
hydraulic cooling fan is integral to the fan shroud
and is located between the radiator and the engine.
The power steering pump supplies the hydraulic
fluid and pressure to rotate the cooling fan blade,
while the electrical part of the fan is controlled by
the JTEC.
The hydraulic fan drive (motor) consists of the
three major following components:
²Steering flow control valve
Fig. 1 COOLANT LEVEL SENSOR ELECTRICAL
CONNECTOR
Fig. 2 COOLANT LEVEL SENSOR REMOVAL/
INSTALLATION
Fig. 3 Coolant Reservoir / Overflow Tank
1 - COOLANT OVERFLOW HOSE
2 - COOLANT RESERVOIR/OVERFLOW TANK
3 - COOLANT LEVEL SENSOR
4 - BOLT
WJENGINE 7 - 27
COOLANT LEVEL SENSOR (Continued)