lock JEEP GRAND CHEROKEE 2002 WJ / 2.G Owner's Manual

NOTE: Arbor Discs 6927A has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.
(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Place Scooter Block/Dial Indicator in position
in axle housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 8). Hold scooter block in place and
zero the dial indicator face to the pointer. Tighten
dial indicator face lock screw.
(7) With scooter block still in position against the
pinion height block, slowly slide the dial indicator
probe over the edge of the pinion height block.
(8) Slide the dial indicator probe across the gap
between the pinion height block and the arbor bar
with the scooter block against the pinion height block
(Fig. 11). When the dial probe contacts the arbor bar,
the dial pointer will turn clockwise. Bring dial
pointer back to zero against the arbor bar, do not
turn dial face. Continue moving the dial probe to the
crest of the arbor bar and record the highest reading.
If the dial indicator can not achieve the zero reading,
the rear bearing cup or the pinion depth gauge set is
not installed correctly.
(9) Select a depth shim equal to the dial indicator
reading plus the pinion depth variance number
etched in the face of the pinion (Fig. 6). For example,
if the depth variance is ±2, add +0.002 in. to the dial
indicator reading.
DIFFERENTIAL BEARING PRELOAD & GEAR
BACKLASH
Differential side bearing preload and gear backlash
is achieved by selective shims positioned behind the
differential side bearing cones. The proper shim
thickness can be determined using slip-fit Dummy
Bearings 6929-A in place of the differential side bear-
ings and a Dial Indicator C-3339. Before proceeding
with the differential bearing preload and gear back-
lash measurements, measure the pinion gear depth
and prepare the pinion for installation. Establishing
proper pinion gear depth is essential to establishing
gear backlash and tooth contact patterns. After the
overall shim thickness to take up differential side
play is measured, the pinion is installed, and the
gear backlash shim thickness is measured. The over-
all shim thickness is the total of the dial indicator
reading and the preload specification added together.
The gear backlash measurement determines the
thickness of the shim used on the ring gear side of
the differential case. Subtract the gear backlash shim
thickness from the total overall shim thickness and
select that amount for the pinion gear side of the dif-
ferential (Fig. 12). Differential shim measurements
are performed with the spreader W-129-B removed.
SHIM SELECTION
NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.
(1) Remove differential side bearings from differ-
ential case.
Fig. 10 GAUGE TOOLS IN HOUSING
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK
Fig. 11 PINION GEAR DEPTH MEASUREMENT
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
WJREAR AXLE - 226RBA 3 - 99
REAR AXLE - 226RBA (Continued)

Adapter 6790
Pinion Depth Set 6955
Bearing Dummy Set 6956
Gauge Block 8144
Shims Dummy 8107
Wrench Spanner 6958
Fixture Holding 6963-A
Remover 7794-A
Splitter Bearing 1130
Installer Gear/Bearing 7913-A
3 - 108 REAR AXLE - 226RBAWJ
REAR AXLE - 226RBA (Continued)

(5) Remove axle bearing from the shaft with, a
press and Splitter 1130 placed between the seal and
bearing (Fig. 27).
(6) Remove seal from axle.
(7) Remove retaining plate from axle shaft.
INSTALLATION
(1) Verify axle shaft retaining plate is flat with a
straight edge.
NOTE: If the plate is warped or the studs are loose
in the plate replace the retaining plate.
(2) Install retaining plate on the axle shaft (Fig.
28).
(3) Apply a coat of multi-purpose grease on sealing
surface of axle seal.
(4) Install seal on the axle shaft with cavity away
from retaining plate (Fig. 28).
(5) Lubricate bearing with Mopar Wheel Bearing
Grease or equivalent. Wipe excess grease from the
bearing.
(6) Install bearing on the axle shaft with Installer
7913 and a press (Fig. 29).
Fig. 27 AXLE BEARING AND SEAL
1 - SPLITTER
2 - AXLE
3 - BLOCKS
4 - PRESS PLATES
Fig. 28 AXLE BEARING AND SEAL COMPONENTS
1 - RETAINING RING
2 - SEAL
3 - AXLE
4 - RETAINING PLATE
5 - AXLE BEARING
Fig. 29 PRESS BEARING ON AXLE
1 - PRESS RAM
2 - INSTALLER
3 - AXLE BEARING
4 - SEAL
5 - RETAINING PLATE
6 - AXLE
3 - 110 REAR AXLE - 226RBAWJ
AXLE BEARINGS/SEALS (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)

(12) Install cover and tighten bolts in a criss-cross
pattern to 41 N´m (30 ft. lbs.).
(13) Refill the differential with Mopar Hypoid
Gear Lubricant or equivalent to bottom of the fill
plug hole.
(14) Install fill hole plug.
(15) Remove support and lower the vehicle.
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING
The most common problem is a chatter noise when
turning corners. Before removing the unit for repair,
drain, flush and refill the axle with the specified
lubricant. A container of Mopar Trac-loktLubricant
(friction modifier) should be added after repair ser-
vice or during a lubricant change.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque (Fig. 56).
(6) If rotating torque is less than 41 N´m (56 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
DISASSEMBLY
(1) Clamp side gear Holding Fixture 6965 in a vise
and position the differential case on the Holding Fix-
ture (Fig. 57).
(2) Remove ring gear if the ring gear is to be
replaced. The Trac-loktdifferential can be serviced
with the ring gear installed.
Fig. 56 ROTATING TORQUE TEST
1 - SPECIAL TOOL WITH BOLT IN CENTER HOLE
2 - TORQUE WRENCH
Fig. 57 DIFFERENTIAL CASE FIXTURE
1 - HOLDING FIXTURE
2 - VISE
3 - DIFFERENTIAL
WJREAR AXLE - 226RBA 3 - 119
DIFFERENTIAL (Continued)

(3) Remove the pinion gear mate shaft lock screw
(Fig. 58).
(4) Remove pinion gear mate shaft with a drift and
hammer (Fig. 59).
(5) Install and lubricate Step Plate C-6960-3 (Fig.
60).
(6) Assemble Threaded Adapter C-6960-1 into top
side gear. Thread Forcing Screw C-6960-4 into
adapter until it becomes centered in adapter plate.
(7) Position a small screw driver in slot of
Threaded Adapter Disc C-6960-1 (Fig. 61) to prevent
adapter from turning.
Fig. 58 MATE SHAFT LOCK SCREW
1 - LOCK SCREW
2 - PINION GEAR MATE SHAFT
Fig. 59 PINION MATE SHAFT
1 - PINION MATE SHAFT
2 - SIDE GEAR
3 - DRIFT
4 - PINION MATE GEAR
Fig. 60 Step Plate
1 - LOWER SIDE GEAR
2 - DIFFERENTIAL CASE
3 - STEP PLATE
Fig. 61 Threaded Adapter Disc
1 - SOCKET
2 - SLOT IN ADAPTER
3 - SCREWDRIVER
4 - STEP PLATE
5 - FORCING SCREW
6 - THREAD ADAPTER DISC
3 - 120 REAR AXLE - 226RBAWJ
DIFFERENTIAL - TRAC-LOK (Continued)

(6) Install lubricated Step Plate C-6960-3 in lower
side gear (Fig. 68).
(7) Install the upper side gear and clutch disc pack
(Fig. 68).
(8) Hold assembly in position. Insert Threaded
Adapter C-6960-1 into top side gear.
(9) Install Forcing Screw C-6960-4 and tighten
screw to slightly compress clutch disc.
(10) Place pinion gears in position in side gears
and verify that the pinion mate shaft hole is aligned.
(11) Rotate case with Turning Bar C-6960-2 until
the pinion mate shaft holes in pinion gears align
with holes in case. It may be necessary to slightly
tighten the forcing screw in order to install the pin-
ion gears.
(12) Tighten forcing screw to 122 N´m (90 ft. lbs.)
maximum to compress the Belleville springs.
(13) Lubricate and install thrust washers behind
pinion gears and align washers with a small screw
driver. Insert mate shaft into each pinion gear to ver-
ify alignment.
(14) Remove Forcing Screw, Step Plate and
Threaded Adapter.
(15) Install pinion gear mate shaft and align holes
in shaft and case.(16) Install pinion mate shaft lock screw finger
tight to hold shaft during differential installation.
(17) Lubricate all differential components with
hypoid gear lubricant.
DIFFERENTIAL CASE
BEARINGS
REMOVAL
(1) Remove differential case from axle housing.
(2) Remove side bearings from the differential case
with Puller/Press C-293-PA, Adapters 8353 and Plug
C-293-3 (Fig. 69).
INSTALLATION
NOTE: If differential side bearings or differential
case are replaced, differential side bearing shim
requirements may change. Refer to Adjustments
(Differential Bearing Preload and Gear Backlash) for
procedures.
Fig. 68 CLUTCH PACK AND UPPER SIDE GEAR
1 - SIDE GEAR AND CLUTCH PACK
2 - DIFFERENTIAL CASE
3 - STEP PLATE
Fig. 69 Differential Bearing Removal
1 - ADAPTERS
2 - BEARING
3 - DIFFERENTIAL
4 - PLUG
5 - PULLER
WJREAR AXLE - 226RBA 3 - 123
DIFFERENTIAL - TRAC-LOK (Continued)

Common causes of brake drag are:
²Parking brake partially applied.
²Loose/worn wheel bearing.
²Seized caliper.
²Caliper binding.
²Loose caliper mounting.
²Mis-assembled components.
²Damaged brake lines.
If brake drag occurs at the front, rear or all
wheels, the problem may be related to a blocked mas-
ter cylinder return port, faulty power booster (binds-
does not release) or the ABS system.
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Rusty caliper slide surfaces
²Improper brake shoes
²Damaged rotor
²Wheel alignment.
²Tire pressure.
A worn, damaged wheel bearing or suspension compo-
nent are further causes of pull. A damaged front tire
(bruised, ply separation) can also cause pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE DRAG OR PULL
Rear drag or pull may be caused by improperly
adjusted park brake shoes or seized parking brake
cables, contaminated lining, bent or binding shoes or
improperly assembled components. This is particu-
larly true when only one rear wheel is involved.However, when both rear wheels are affected, the
master cylinder or ABS system could be at fault.
BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
mile or two. However, if the lining is both soaked and
dirt contaminated, cleaning and or replacement will
be necessary.
BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of
leaking calipers or worn seals, driving through deep
water puddles, or lining that has become covered with
grease and grit during repair. Contaminated lining
should be replaced to avoid further brake problems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components
may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and
pull. A worn or damaged tire can also cause pull.
NOTE: Propshaft angle can also cause vibration/
shudder.
Severely worn tires with very little tread left can
produce a grab-like condition as the tire loses and
recovers traction. Flat-spotted tires can cause vibra-
tion and generate shudder during brake operation.
Tire damage such as a severe bruise, cut, ply separa-
tion, low air pressure can cause pull and vibration.
BRAKE NOISES
Some brake noise is common on some disc brakes
during the first few stops after a vehicle has been
parked overnight or stored. This is primarily due to
the formation of trace corrosion (light rust) on metal
surfaces. This light corrosion is typically cleared from
the metal surfaces after a few brake applications
causing the noise to subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that
are wet or contaminated with brake fluid, grease, or oil.
Glazed linings and rotors with hard spots can also con-
tribute to squeak. Dirt and foreign material embedded
in the brake lining will also cause squeak/squeal.
A very loud squeak or squeal is frequently a sign of
severely worn brake lining. If the lining has worn
through to the brake shoes in spots, metal-to-metal
contact occurs. If the condition is allowed to continue,
rotors may become so scored that replacement is nec-
essary.
5 - 4 BRAKES - BASEWJ
BRAKES - BASE (Continued)

SPECIAL TOOLS
BASE BRAKESBRAKE FLUID LEVEL SWITCH
REMOVAL
(1) Remove the wire connector from the fluid level
sensor.
(2) From the same side of the master cylinder res-
ervoir release the sensor locking taps with a small
screw driver.
(3) Pull the sensor out of the reservoir from the
connector side of the sensor.
INSTALLATION
(1) Install the sensor with a new o-ring into the
reservoir until the locking tabs are engaged.
(2) Install the wire connector to the fluid level sen-
sor.
RED BRAKE WARN INDICATOR
SWITCH
DESCRIPTION
A red warning lamp is used for the service brake
portion of the hydraulic system. The lamp is located
in the instrument cluster.
OPERATION
The lamp is turned on momentarily when the igni-
tion switch is turn to the on position. This is a self
test to verify the lamp is operational.
The red warning light alerts the driver if the fluid
level is low or the parking brakes are applied. A red
warning lamp with an amber warning lamp may
indicate a electronic brake distribution fault.
DIAGNOSIS AND TESTING - RED BRAKE
WARNING LAMP
The red warning lamp illuminates when the park-
ing brake is applied or when the fluid level in the
master cylinder is low. It will also illuminate at start
up as part of a bulb check.
If the light comes on, first verify that the parking
brakes are fully released. Then check pedal action
and fluid level. If a problem is confirmed, inspect the
brake hydraulic system for leaks.
A red warning lamp with a amber warning lamp
may indicate a electronic brake distribution fault.
Installer Caliper Dust Boot 8280
Handle C-4171
Adapter Pressure Bleeder 6921
WJBRAKES - BASE 5 - 7
BRAKES - BASE (Continued)

ADJUSTABLE PEDAL SWITCH
REMOVAL
(1) Remove the steering column opening cover
(Fig. 2)(Refer to 23 - BODY/INSTRUMENT PANEL/
STEERING COLUMN OPENING COVER - REMOV-
AL).
(2) Disconnect the electrical connector from the
adjustable pedal switch.
(3) Remove the switch from the steering column
opening cover by squeezing the retaining clips
together and pushing the switch outwards (Fig. 3).
INSTALLATION
(1) Install the switch to the steering column open-
ing cover by pushing the switch inwards seating the
retaining clips to the steering column opening cover
(Fig. 3).
(2) Reconnect the electrical connector to the
adjustable pedal switch.
(3) Install the steering column opening cover (Fig.
2)(Refer to 23 - BODY/INSTRUMENT PANEL/
STEERING COLUMN OPENING COVER - INSTAL-
LATION).
BRAKE LINES
DESCRIPTION
Flexible rubber hose is used at both front brakes,
rear brakes and at the rear axle junction block. Dou-
ble walled steel tubing is used. Double inverted style
and ISO style flares are used on the brake lines.
DIAGNOSIS AND TESTING - BRAKE HOSES
AND LINES
Flexible rubber hose is used at both front and rear
brakes and at the rear axle junction block. Inspect
the hoses whenever the brake system is serviced, at
every engine oil change, or whenever the vehicle is in
for service.
Inspect the hoses for surface cracking, scuffing, or
worn spots. Replace any brake hose immediately if
the fabric casing of the hose is exposed due to cracks
or abrasions.
Also check brake hose installation. Faulty installa-
tion can result in kinked, twisted hoses, or contact
with the wheels and tires or other chassis compo-
nents. All of these conditions can lead to scuffing,
cracking and eventual failure.
The steel brake lines should be inspected periodi-
cally for evidence of corrosion, twists, kinks, leaks, or
other damage. Heavily corroded lines will eventually
rust through causing leaks. In any case, corroded or
damaged brake lines should be replaced.
Factory replacement brake lines and hoses are rec-
ommended to ensure quality, correct length and supe-
rior fatigue life. Care should be taken to make sure
that brake line and hose mating surfaces are clean
and free from nicks and burrs. Also remember that
right and left brake hoses are not interchangeable.
Use new copper gaskets at all caliper connections.
Be sure brake line connections are properly made
(not cross threaded) and tightened to recommended
torque.
Fig. 2 STEERING COLUMN OPENING COVER
REMOVAL/INSTALL
1 - INSTRUMENT PANEL TOP PAD
2 - STEERING COLUMN OPENING COVER
3 - SCREW (3)
Fig. 3 ADJUSTABLE PEDAL SWITCH
1 - RETAINING CLIPS
2 - ELECTRICAL CONNECTION
5 - 8 BRAKES - BASEWJ