Drive Shaft JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

FLUID FILL/CHECK
LOCATIONS
DESCRIPTION
The fluid check/fill point locations are located in
each applicable service manual section.
MAINTENANCE SCHEDULES
DESCRIPTION
9Maintenance Schedule Information not included in
this section, is located in the appropriate Owner's
Manual.9
HOISTING
STANDARD PROCEDURE - HOISTING
RECOMMENDATIONS
Refer to the Owner's Manual for emergency vehicle
lifting procedures.
When properly positioned, a floor jack can be used
to lift a Jeep vehicle (Fig. 4). Support the vehicle in
the raised position with jack stands at the front and
rear ends of the frame rails.CAUTION: Do not attempt to lift a Jeep vehicle with
a floor jack positioned under:
²A body side sill.
²A steering linkage component.
²A drive shaft.
²The engine or transmission oil pan.
²The fuel tank.
²A front suspension arm.
²Transfer case.
NOTE: Use the correct sub-frame rail or frame rail
lifting locations only.
HOIST
Refer to the Owner's Manual for emergency vehicle
lifting procedures.
A vehicle can be lifted with:
²A single-post, frame-contact hoist.
²A twin-post, chassis hoist.
²A ramp-type, drive-on hoist.
NOTE: When a frame-contact type hoist is used,
verify that the lifting pads are positioned properly.
WARNING: THE HOISTING AND JACK LIFTING
POINTS PROVIDED ARE FOR A COMPLETE VEHI-
CLE. WHEN A CHASSIS OR DRIVETRAIN COMPO-
NENT IS REMOVED FROM A VEHICLE, THE
CENTER OF GRAVITY IS ALTERED MAKING SOME
HOISTING CONDITIONS UNSTABLE. PROPERLY
SUPPORT OR SECURE VEHICLE TO HOISTING
DEVICE WHEN THESE CONDITIONS EXIST.
Fig. 4 Correct Vehicle Lifting Locations
1 - Frame Contact Lift (Single Post)
Chassis Lift (Non-Axle Dual Post)
Outboard Lift (Dual Post)
Floor Jack
2 - Floor Jack
KJLUBRICATION & MAINTENANCE 0 - 5

towing device, use tow dollies under the opposite end
of the vehicle. A vehicle with flatbed device can also
be used to transport a disabled vehicle (Fig. 6).
SAFETY PRECAUTIONS
CAUTION: The following safety precautions must be
observed when towing a vehicle:
²Secure loose and protruding parts.
²Always use a safety chain system that is inde-
pendent of the lifting and towing equipment.
²Do not allow towing equipment to contact the
disabled vehicle's fuel tank.
²Do not allow anyone under the disabled vehicle
while it is lifted by the towing device.
²Do not allow passengers to ride in a vehicle
being towed.
²Always observe state and local laws regarding
towing regulations.
²Do not tow a vehicle in a manner that could
jeopardize the safety of the operator, pedestrians or
other motorists.
²Do not attach tow chains, T-hooks, or J-hooks to
a bumper, steering linkage, drive shafts or a non-re-
inforced frame hole.
²Do not tow a heavily loaded vehicle. Use a flat-
bed device to transport a loaded vehicle.
TWO-WHEEL-DRIVE VEHICLE TOWING
DaimlerChrysler Corporation recommends that a
vehicle be towed with the rear end lifted, whenever
possible.
WARNING: WHEN TOWING A DISABLED VEHICLE
AND THE DRIVE WHEELS ARE SECURED IN A
WHEEL LIFT OR TOW DOLLIES, ENSURE THE
TRANSMISSION IS IN THE PARK POSITION (AUTO-
MATIC TRANSMISSION) OR A FORWARD DRIVE
GEAR (MANUAL TRANSMISSION).WARNING: ENSURE VEHICLE IS ON A LEVEL SUR-
FACE OR THE WHEELS ARE BLOCKED TO PRE-
VENT VEHICLE FROM ROLLING.
TWO WHEEL DRIVE TOWING-REAR END LIFTED
CAUTION: Do not use steering column lock to
secure steering wheel during towing operation.
2WD vehicles can be towed with the front wheels
on the surface for extended distances at speeds not
exceeding 48 km/h (30 mph).
(1) Attach wheel lift device to rear wheels.
(2) Place the transmission in neutral.
(3) Raise vehicle to towing position.
(4) Attach safety chains. Route chains so not to
interfere with tail pipe when vehicle is lifted.
(5) Turn the ignition switch to the OFF position to
unlock the steering wheel.
CAUTION: Do not use steering column lock to
secure steering wheel during towing operation.
(6) Secure steering wheel in straight ahead posi-
tion with a clamp device designed for towing.
(7) Place transmission in park.
TWO WHEEL DRIVE TOWING-FRONT END LIFTED
CAUTION: Many vehicles are equipped with air
dams, spoilers, and/or ground effect panels. To
avoid component damage, a wheel-lift towing vehi-
cle or a flat-bed hauling vehicle is recommended.
(1) Attach wheel lift device to rear wheels.
(2) Place the transmission in neutral.
(3) Raise the rear of the vehicle off the ground and
install tow dollies under rear wheels.
(4) Attach wheel lift device to front wheels and
raise vehicle to towing position.
(5) Attach the safety chains.
CAUTION: Do not use steering column lock to
secure steering wheel during towing operation.
(6) Turn the ignition switch to the OFF position to
unlock the steering wheel.
(7) Secure steering wheel in straight ahead posi-
tion with a clamp device designed for towing.
(8) Place transmission in park.
FOUR-WHEEL-DRIVE VEHICLE TOWING
DaimlerChrysler Corporation recommends that a
4WD vehicle be transported on a flat-bed device. A
Wheel-lift device can be used providedthe trailing
wheels are off the ground and positioned in
tow dollies.
Fig. 6 Tow Vehicles With Approved Equipment
KJLUBRICATION & MAINTENANCE 0 - 7
TOWING (Continued)

BUSHINGS
REMOVAL - STABILIZER BAR BUSHINGS
(1) Raise vehicle on hoist.
(2) Remove the stabilizer bushing clamps.
(3) Remove the stabilizer bushings from the stabi-
lizer bar.
INSTALLATION - STABILIZER BAR BUSHINGS
(1) Install the stabilizer bushings to the stabilizer
bar.
(2) Install the stabilizer bushing clamps. Tighten
the nuts to 149 N´m (110 ft.lbs.).
(3) Lower the vehicle.
HUB / BEARING
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL).
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose will result. Provide a suitable support to hang
the caliper securely.
(4) Remove the disc brake rotor (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL).
(5) Remove the wheel speed sensor (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - REMOVAL).
(6) Remove the bracket securing the wheel speed
sensor wire.
(7) Remove the axle shaft nut. (if equipped with
four wheel drive)
(8) Remove the three mounting bolts for the hub/
bearing assembly.
(9) Remove the hub/bearing.
INSTALLATION
(1) Install the hub/bearing assembly to the vehicle.
(2) Install the three mounting bolts for the hub/
bearing. Tighten the bolt to 130 N´m (96 ft.lbs.).
(3) Install the axle shaft nut. Tighten the nut to
135 N´m (100 ft.lbs.). (if equipped with four wheel
drive)
(4) Install the bracket to the wheel speed sensor
wire.
(5) Install the wheel speed sensor to the hub.
Tighten the bolt to 13.5 N´m (10 ft.lbs.) (Refer to 5 -BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - INSTALLATION).
(6) Install the disc brake rotor (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(7) Install the disc brake caliper adapter. Tighten
the nut to 135 N´m (100 ft.lbs.) (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(8) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
KNUCKLE
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the caliper adapter. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - REMOVAL).
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose will result. Provide a suitable support to hang
the caliper securely.
(4) Remove the disc brake rotor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL).
(5) Remove the wheel speed sensor. (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - REMOVAL).
(6) Remove the axle shaft nut. (if equipped with
four wheel drive)
(7) Remove the hub/bearing. (Refer to 2 - SUS-
PENSION/FRONT/HUB / BEARING - REMOVAL).
(8) Remove the outer tie rod end. (Refer to 19 -
STEERING/LINKAGE/TIE ROD END - REMOVAL).
(9) Remove the lower ball joint nut.
(10) Seperate the lower ball joint from the suspen-
sion arm using tool C±4150A.
(11) Remove the upper ball joint nut.
(12) Seperate the upper ball joint from the knuckle
using tool C±4150A.
(13) Remove the knuckle from the vehicle.
INSTALLATION
(1) Install the knuckle to the vehicle.
(2) Install the upper ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.).
(3) Install the lower ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.).
(4) Install the outer tie rod end. (Refer to 19 -
STEERING/LINKAGE/TIE ROD END - INSTALLA-
TION).
KJFRONT 2 - 9

(5) Install the hub/bearing. (Refer to 2 - SUSPEN-
SION/FRONT/HUB / BEARING - INSTALLATION).
(6) Install the axle shaft nut. Tighten the nut to
135 N´m (96 ft.lbs.).(if equipped with four wheel
drive).
(7) Install the wheel speed sensor. (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - INSTALLATION).
(8) Install the disc brake rotor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(9) Install the caliper adapter. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(10) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(11) Perform the set toe procedure (Refer to 2 -
SUSPENSION/WHEEL ALIGNMENT - STANDARD
PROCEDURE).
LOWER BALL JOINT
DIAGNOSIS AND TESTING - LOWER BALL
JOINT
(1) Raise the vehicle on a drive-on hoist.
NOTE: If a drive-on hoist is not available, use
wooden blocks with jack stands to support the
lower control arm in the ball joint area. Place the
jack stands appropriately and lower the hoist plac-
ing weight on the lower control arm. The lower con-
trol arms should now be supporting the vehicle
weight.
(2) With the use of jack stands, lift the front end
off the hoist and position wooden blocks underneath
both lower control arms supporting the vehicles
weight.
(3) Remove the tire and wheel assembly.
(4) Attach a dial indicator to the base of the lower
control arm and align the dial indicator's contact
point with the direction of the stud axis, touch the
machined flat on the knuckle and zero the dial indi-
cator. (Fig. 2)
NOTE: Use care when applying the load to the
knuckle, so the parts are not damaged using care
not to tear the boot.
(5) From the front of the vehicle, insert a pry bar
to get it rested on the lower control arm and use
lever principle to push the knuckle up until the arm
of the dial indicator no longer moves.(6) Record the ball joint movement on each side of
the vehicle. The end play is acceptable with no more
than 1.5mm of end play back to back.LOWER CONTROL ARM
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the lower clevis bracket bolt at the
lower control arm.
(4) Remove the stabilizer link bolt at the lower
control arm.
(5) Remove the lower ball joint nut.
(6) Separate the lower ball joint from the lower
control arm using tool C-4150A.
NOTE: Marking the lower control arm pivot bolts
front and rear will aid in the assembly procedure.
(7) Mark the lower control arm pivot bolts front
and rear.
(8) Remove the front cam/pivot bolt. (Fig. 3)
(9) Remove the rear cam/pivot bolt. (Fig. 3)
(10) Remove the lower control arm from the vehi-
cle.
INSTALLATION
(1) Install the lower control arm to the vehicle.
(2) Install the rear cam/pivot bolt.
(3) Install the front cam/pivot bolt.
(4) Install the lower ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.)
Fig. 2 SUSPENSION IN THE CURB POSITION
1-PRYBAR
2 - BALL JOINT
3 - DIAL INDICATOR
4 - WOODEN BLOCK OR SUPPORT
5 - CLAMP
2 - 10 FRONTKJ
KNUCKLE (Continued)

LOWER BALL JOINT
REMOVAL
(1) Remove the tire and wheel assembly.
(2) Remove the brake caliper and rotor (Refer to 5
- BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL).
(3) Disconnect the tie rod from the steering
knuckle (Refer to 19 - STEERING/LINKAGE/TIE
ROD END - REMOVAL).
(4) Remove the steering knuckle (Refer to 2 - SUS-
PENSION/FRONT/KNUCKLE - REMOVAL).
(5) Move the halfshaft to the side and support the
halfshaft out of the way (If Equipped).
NOTE: Extreme pressure lubrication must be used
on the threaded portions of the tool. This will
increase the longevity of the tool and insure proper
operation during the removal and installation pro-
cess.
(6) Secure the steering knuckle in a vise.
(7) Press the ball joint from the steering knuckle
using special tools C-4212±F (PRESS), 8859-2
(RECEIVER) and 8859-1 (DRIVER) (Fig. 7).
INSTALLATION
NOTE: Extreme pressure lubrication must be used
on the threaded portions of the tool. This will
increase the longevity of the tool and insure proper
operation during the removal and installation pro-
cess.(1) Install the ball joint into the steering knuckle
and press in using special tools C-4212±F (press),
8859-3 (driver) and 6761 (receiver) (Fig. 8).
(2) Install the ball joint boot.
(3) Remove the support for the halfshaft and
install into position (If Equipped).
(4) Install the steering knuckle (Refer to 2 - SUS-
PENSION/FRONT/KNUCKLE - INSTALLATION).
(5) Install the tie rod end into the steering knuckle
(Refer to 19 - STEERING/LINKAGE/TIE ROD END -
INSTALLATION).
(6) Install and tighten the halfshaft nut to 136
N´m (100 ft. lbs.).
(7) Install the brake caliper and rotor (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(8) Install the tire and wheel assembly (Refer to 22
- TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
(9) Check the vehicle ride height (Refer to 2 - SUS-
PENSION/WHEEL ALIGNMENT - STANDARD
PROCEDURE).
(10) Perform a wheel alignment (Refer to 2 - SUS-
PENSION/WHEEL ALIGNMENT - STANDARD
PROCEDURE).
Fig. 7 LOWER BALL JOINT
1 - 8859-1 DRIVER
2 - C-4212F PRESS
3 - 8859-2 RECEIVER
Fig. 8 LOWER BALL JOINT
1 - 6761 RECEIVER
2 - 8859-3 DRIVER
3 - C-4212F PRESS
KJSUSPENSION 2s - 5

DIFFERENTIAL & DRIVELINE
TABLE OF CONTENTS
page page
PROPELLER SHAFT......................1
HALF SHAFT...........................10
FRONT AXLE - 186FIA....................19REAR AXLE - 198RBI.....................49
REAR AXLE-81/4.......................86
PROPELLER SHAFT
TABLE OF CONTENTS
page page
PROPELLER SHAFT
DIAGNOSIS AND TESTING - PROPELLER
SHAFT...............................1
STANDARD PROCEDURES - PROPELLER
SHAFT ANGLE........................3
SPECIFICATIONS
PROPELLER SHAFT....................6
SPECIAL TOOLS........................6
PROPELLER SHAFT - FRONT
REMOVAL.............................6INSTALLATION..........................6
PROPELLER SHAFT - REAR
REMOVAL.............................7
INSTALLATION..........................7
SINGLE CARDAN UNIVERSAL JOINTS
DISASSEMBLY..........................8
ASSEMBLY.............................9
PROPELLER SHAFT
DIAGNOSIS AND TESTING - PROPELLER
SHAFT
VIBRATION
Tires that are out-of-round, or wheels that are
unbalanced, will cause a low frequency vibration.
Brake rotors that are unbalanced will cause a
harsh, low frequency vibration.Driveline vibration can also result from loose or
damaged engine mounts.
Propeller shaft vibration increases as the vehicle
speed is increased. A vibration that occurs within a
specific speed range is not usually caused by a pro-
peller shaft being unbalanced. Defective joints or an
incorrect propeller shaft angle, are usually the cause
of such a vibration.
KJDIFFERENTIAL & DRIVELINE 3 - 1

DRIVELINE VIBRATION
Drive Condition Possible Cause Correction
Propeller Shaft Noise 1. Undercoating or other foreign
material on shaft.1. Clean exterior of shaft and wash
with solvent.
2. Loose U-joint clamp screws. 2. Install new clamps and screws
and tighten to proper torque.
3. Loose or bent U-joint yoke or
excessive runout.3. Install new yoke.
4. Incorrect driveline angularity. 4. Measure and correct driveline
angles.
5. Worn joint. 5. Install new joint.
6. Propeller shaft damaged or out
of balance.6. Installl new propeller shaft.
7. Broken rear spring. 7. Install new rear spring.
8. Excessive runout or unbalanced
condition.8. Re-index propeller shaft, test, and
evaluate.
9. Excessive drive pinion gear shaft
runout.9. Re-index propeller shaft and
evaluate.
10. Excessive axle yoke deflection. 10. Inspect and replace yoke if
necessary.
11. Excessive transfer case runout. 11. Inspect and repair as necessary.
Joint Noise 1. Loose U-joint clamp screws. 1. Install new clamps and screws
and tighten to proper torque.
2. Lack of lubrication. 2. Replace joints as necessary.
BALANCE
NOTE: Removing and re-indexing the propeller
shaft 180É relative to the yoke may eliminate some
vibrations.
If propeller shaft is suspected of being unbalanced,
it can be verified with the following procedure:
(1) Raise the vehicle.
(2) Clean all the foreign material from the propel-
ler shaft and the universal joints.
(3) Inspect the propeller shaft for missing balance
weights, broken welds, and bent areas.If the pro-
peller shaft is bent, it must be replaced.
(4) Inspect the universal joints to ensure that they
are not worn, are properly installed, and are cor-
rectly aligned with the shaft.
(5) Check the universal joint clamp screws torque.
(6) Remove the wheels and tires. Install the wheel
lug nuts to retain the brake drums or rotors.
(7) Mark and number the shaft six inches from the
yoke end at four positions 90É apart.
(8) Run and accelerate the vehicle until vibration
occurs. Note the intensity and speed the vibration
occurred. Stop the engine.(9) Install a screw clamp at position 1 (Fig. 1).
Fig. 1 CLAMP AT POSITION 1
1 - CLAMP
2 - SCREWDRIVER
3 - 2 PROPELLER SHAFTKJ
PROPELLER SHAFT (Continued)

FRONT AXLE - 186FIA
TABLE OF CONTENTS
page page
FRONT AXLE - 186FIA
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - AXLE..........20
REMOVAL.............................24
INSTALLATION.........................24
ADJUSTMENTS........................25
SPECIFICATIONS - FRONT AXLE...........33
SPECIAL TOOLS
FRONT AXLE........................34
AXLE SHAFTS
REMOVAL.............................37
INSTALLATION.........................37
AXLE SHAFT SEALS
REMOVAL.............................37
INSTALLATION.........................38
AXLE BEARINGS
REMOVAL.............................38INSTALLATION.........................38
PINION SEAL
REMOVAL.............................38
INSTALLATION.........................39
DIFFERENTIAL
REMOVAL.............................40
DISASSEMBLY.........................41
ASSEMBLY............................41
INSTALLATION.........................42
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................43
INSTALLATION.........................44
PINION GEAR/RING GEAR
REMOVAL.............................44
INSTALLATION.........................46
FRONT AXLE - 186FIA
DESCRIPTION
The 186FIA (Model 30) axle consists of an alumu-
num center section with an axle tube extending from
one side. The tube is pressed into the differential
housing. The integral type housing, hypoid gear
design has the centerline of the pinion set below the
centerline of the ring gear.
The differential case is a one-piece design. The differ-
ential pinion mate shaft is retained with a roll-pin. Dif-
ferential bearing preload and ring gear backlash is
adjusted by the use of shims (select thickness). The
shims are located between the differential bearing cups
and the axle housing. Pinion bearing preload is set and
maintained by the use of a collapsible spacer.
The power is transferred from the axle through two
constant velocity (C/V) drive shafts to the wheel hubs.
The differential cover provides a means for inspec-
tion and service without removing the axle from the
vehicle. The cover has a vent tube used to relieve
internal pressure caused by vaporization and inter-
nal expansion.
OPERATION
The axle receives power from the transfer case through
the front propeller shaft. The front propeller shaft is con-
nected to the pinion gear which rotates the differential
through the gear mesh with the ring gear bolted to thedifferential case. The engine power is transmitted to the
axle shafts through the pinion mate and side gears. The
side gears are splined to the axle shafts.
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 1).
Fig. 1 DIFFERENTIAL-STRAIGHT AHEAD DRIVING
1 - STRAIGHT AHEAD DRIVING
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
KJFRONT AXLE - 186FIA 3 - 19

When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
2). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, 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 mate shaft can also cause a
snapping 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 changes
when 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:
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 rear end
vibration. Do not overlook engine accessories, brack-
ets and drive belts.
All driveline components should be examined
before starting any repair.
Fig. 2 DIFFERENTIAL-ON TURNS
1 - PINION GEARS ROTATE ON PINION SHAFT
3 - 20 FRONT AXLE - 186FIAKJ
FRONT AXLE - 186FIA (Continued)

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.
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.
3. End-play in pinion bearings. 3. Refer to pinion pre-load
information and correct as
necessary.
4. Excessive gear backlash
between the ring gear and pinion.4. Check adjustment of the ring
gear and pinion backlash. Correct
as necessary.
5. Improper adjustment of pinion
gear bearings.5. Adjust the pinion bearings
pre-load.
6. Loose pinion yoke nut. 6. Tighten the pinion yoke nut.
7. Scuffed gear tooth contact
surfaces.7. Inspect and replace 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.
KJFRONT AXLE - 186FIA 3 - 21
FRONT AXLE - 186FIA (Continued)