wheel bearing JEEP LIBERTY 2002 KJ / 1.G Owner's Manual

DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
3 - 52 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)

(10) Install axle vent hose.
(11) Install propeller shaft with reference marks.
(12) Install the wheels and tires.
(13) Add gear lubricant to specifications, if neces-
sary.
(14) Remove lifting device from axle and lower the
vehicle.
(15) Tighten the lower control arm bolts to torque
specification.
ADJUSTMENTS
ADJUSTMENT
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
9). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 96.850 mm (3.813 in.). The standard depth pro-
vides the best teeth contact pattern. Refer to Back-
lash and Contact Pattern Analysis Paragraph in this
section for additional information.
Compensation for pinion depth variance is
achieved with select shims. The shims are placed
under the inner pinion bearing cone (Fig. 10).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion gear. Add or subtract the thickness of
the original depth shims to compensate for the differ-
ence in the depth variances. Refer to the Depth Vari-
ance charts.Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus amount needed.
Note the etched number on the face of the drive
pinion gear (±1, ±2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shim(s). If the num-
ber is positive, subtract that value from the thickness
of the depth shim(s). If the number is 0 no change is
necessary. Refer to the Pinion Gear Depth Variance
Chart.
Fig. 8 LOWER SUSPENSION ARM
1 - AXLE BRACKET BOLT
2 - LOWER CONTROL ARM
3 - BODY BRACKET BOLTFig. 9 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 10 Shim Locations
1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM
5 - COLLAPSIBLE SPACER
KJREAR AXLE - 198RBI 3 - 55
REAR AXLE - 198RBI (Continued)

AXLE SHAFTS
REMOVAL
(1) Place transmission in neutral and raise and
support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake drum.
(4) Remove axle retainer plate nuts from the rear
of the axle flange.
(5) Pull axle shaft from the axle with Slide Ham-
mer 7420 and Adapter 6790. Mount the adapter to
the axle with lug nuts.
NOTE: It is normal that the axle bearing race is
loose in the axle tube.
INSTALLATION
(1) Insall axle into the axle tube with the flat area
of the retainer plate upward.
(2) Insert retaining plate studs into the brake
backing plate and axle tube flange.
(3) Install retainer nuts and tighten to 47-75 N´m
(35-55 ft. lbs.).
(4) Install the brake drum.
(5) Install wheel and tire.
(6) Check and fill the differential with gear lubri-
cant.
(7) Lower vehicle.
PILOT STUDS C-3288-B
PULLER 6790
DIAL INDICATOR C-3339
INSTALLER C-3718
KJREAR AXLE - 198RBI 3 - 65
REAR AXLE - 198RBI (Continued)

INSTALLATION
NOTE: Verify axle shaft retaining plate is flat with a
straight edge. If the plate is warped replace the
plate.
(1) Install retaining plate on the axle shaft (Fig.
28).
(2) Apply a coat of multi-purpose grease on sealing
surface of axle seal.
(3) Install seal on the axle shaft with cavity away
from retaining plate (Fig. 28).
(4) Lubricate bearing with MopartWheel Bearing
Grease or equivalent. Wipe excess grease from the
bearing.
(5) Install bearing on the axle shaft with Installer
7913 and a press (Fig. 29).
(6) Press retaining ring onto axle shaft with
Installer 7913 and a press (Fig. 30).
(7) Install axle in vehicle.
Fig. 29 BEARING ON AXLE
1 - PRESS RAM
2 - INSTALLER - 7913
3 - AXLE BEARING
4 - SEAL
5 - RETAINING PLATE
6 - AXLE
Fig. 30 BEARING RETAINING RING ON AXLE
1 - PRESS
2 - AXLE
3 - AXLE BEARING
4 - INSTALLER
5 - SOFT METAL RETAINING RING
Fig. 28 AXLE BEARING AND SEAL COMPONENTS
1 - RETAINING RING
2 - SEAL
3 - AXLE
4 - RETAINING PLATE
5 - AXLE BEARING
KJREAR AXLE - 198RBI 3 - 67
AXLE BEARING/SEAL (Continued)

PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake rotors drums.
(4) Mark propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate pinion gear three or four times and ver-
ify that pinion rotates smoothly.
(7) Measure and record torque to rotate the pinion
gear with an inch pound dial-type torque wrench.
(8) With a short piece of pipe and Spanner Wrench
6958 remove the pinion nut and washer (Fig. 31).
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281. (Fig. 32)
(10) Remove pinion seal with Remover 7794-A and
a slide hammer (Fig. 33).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
seal installer (Fig. 34).
(2) Install yoke on the pinion gear with Installer
C-3718 and Spanner Wrench 6958 (Fig. 35).(3) Install anewnut on the pinion gear.Tighten
the nut only enough to remove the shaft end
play.
CAUTION: Do not exceed the minimum torque 271
N´m (200 ft. lbs.) when installing the pinion yoke
retaining nut at this point. Damage to collapsible
spacer or bearings may result.
(4) Rotate the pinion a minimum of ten times and
verify pinion rotates smoothly.
(5) Measure and recore pinion torque to rotate
with an inch pound torque wrench. Torque to rotate
should be equal to the reading recorded during
removal, plus 0.56 N´m (5 in. lbs.) (Fig. 36).
Fig. 31 YOKE SPANNER WRENCH
1 - PINION YOKE
2 - WRENCH
3 - PIPE
Fig. 32 PINION YOKE REMOVER
1 - WRENCH
2 - YOKE
3 - REMOVER
Fig. 33 PINION SEAL REMOVER
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
3 - 68 REAR AXLE - 198RBIKJ

(8) Fill differential with gear lubricant.
(9) Install the brake drums
(10) Install wheel and tire assemblies.
(11) Lower the vehicle.
COLLAPSIBLE SPACER
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake drums.
(4) Mark the propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate the pinion gear three or four times.
(7) Measure and record torque to rotate the pinion
gear with an inch pound dial-type torque wrench.
(8) Hold pinion yoke with Spanner Wrench 6958
and remove pinion nut and washer.
(9) Remove the pinion yoke with Remover C-452
and Flange Wrench C-3281 (Fig. 38).
(10) Remove pinion shaft seal with a pry tool or a
slide hammer mounted screw.
(11) Remove front pinion bearing using a pair of
pick tools. Pull the bearing straight off the pinion
gear shaft. If the bearing becomes bound on the pin-
ion shaft, lightly tap the end of the pinion gear with
a rawhide/rubber hammer.
(12) Remove the collapsible spacer.
INSTALLATION
(1) Install anewcollapsible preload spacer on pin-
ion shaft.
(2) Install pinion front bearing.(3) Apply a light coating of gear lubricant on the
lip of pinion seal and install anewseal with an
appropriate installer (Fig. 39).
(4) Install yoke with Screw 8112, Cup 8109 and
Spanner Wrench 6958 (Fig. 40).
(5) Install yoke washer andnewnut on the pinion
gear. Tighten the nut to 271 N´m (200 ft. lbs.).
CAUTION: Never loosen pinion gear nut to decrease
pinion gear bearing rotating torque and never
exceed specified preload torque. If preload torque
or rotating torque is exceeded a new collapsible
spacer must be installed.
Fig. 38 PINION YOKE
1 - FLANGE WRENCH
2 - YOKE
3 - REMOVER
Fig. 39 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 40 PINION YOKE INSTALLER
1 - INSTALLER
2 - PINION YOKE
3 - WRENCH
3 - 70 REAR AXLE - 198RBIKJ
PINION SEAL (Continued)

(6) Using yoke with Spanner Wrench 6958 and a
torque wrench set at 474 N´m (350 ft. lbs.), (Fig. 41)
slowly tighten the nut in 6.8 N´m (5 ft. lbs.) incre-
ments until the rotating torque is achieved. Measure
the rotating torque frequently to avoid over crushing
the collapsible spacer (Fig. 42).
NOTE: If more than 474 N´m (350 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. 42). 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
aligned.
(9) Install rear brake drums.
(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 differential cover and drain fluid.
(3) 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.
(4) Remove axle shafts.
(5)
Note the reference letters stamped on the bearing
caps and housing machined sealing surface (Fig. 43).
Fig. 41 YOKE SPANNER WRENCH
1 - PINION YOKE
2 - WRENCH
3 - PIPE
Fig. 42 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE
Fig. 43 BEARING CAP IDENTIFICATION
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
KJREAR AXLE - 198RBI 3 - 71
COLLAPSIBLE SPACER (Continued)

(6) Install the bearing caps in their original loca-
tions (Fig. 50).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten the bearing cap bolts to 64-91 N´m
(47-67 ft. lbs.).
(10) Install the axle shafts.
(11) Apply a 6.35mm (1/4 in.) bead of red Mopar
Silicone Rubber Sealant or equivalent to the housing
cover (Fig. 51).
CAUTION: If cover is not installed within 3 to 5 min-
utes, the cover must be cleaned and new RTV
applied or adhesion quality will be compromised.
(12) Install the cover and tighten cover bolts in a
criss-cross pattern to 38-45 N´m (28-33 ft. lbs.).
(13) Refill the differential with lubricant and
install fill plug.
(14) Remove support and lower the vehicle.
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT
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. 52).
(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.
Fig. 50 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 51 DIFFERENTIAL COVER - TYPICAL
1 - SEALING SURFACE
2 - SEALANT BEAD
3 - SEALANT THICKNESS
3 - 74 REAR AXLE - 198RBIKJ
DIFFERENTIAL (Continued)

traction. Pulling power is provided continuously until
both wheels loose traction. If both wheels slip due to
unequal traction, Trac-lokŸ operation is normal. In
extreme cases of differences of traction, the wheel
with the least traction may spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changeswhen the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
NOTE: All driveline components should be exam-
ined before starting any repair.
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
3 - 88 REAR AXLE-81/4KJ
REAR AXLE - 8 1/4 (Continued)

DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
KJREAR AXLE - 8 1/4 3 - 89
REAR AXLE - 8 1/4 (Continued)