check engine JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

VEHICLE EMISSION CONTROL
INFORMATION (VECI) LABEL
DESCRIPTION
All models have a Vehicle Emission Control Infor-
mation (VECI) Label. DaimlerChrysler permanently
attaches the label in the engine compartment (Fig.
4). The label cannot be removed without defacing
label information and destroying label.
The label contains the vehicle's emission specifica-
tions and vacuum hose routings. All hoses must be
connected and routed according to the label.
The label also contains an engine vacuum sche-
matic. There are unique labels for vehicles built for
sale in the state of California and the country of
Canada. Canadian labels are written in both the
English and French languages.
The VECI label contains the following:
²Engine family and displacement
²Evaporative family
²Emission control system schematic
²Certification application
²Engine timing specifications (if adjustable)
²Idle speeds (if adjustable)
²Spark plug and gap
VEHICLE IDENTIFICATION
NUMBER
DESCRIPTION
The Vehicle Identification Number (VIN) plate is
located on the lower left A-pillar and is visible
through the windshield (Fig. 5). The VIN contains 17
characters that provide data concerning the vehicle.
Refer to the VIN decoding chart to determine the
identification of a vehicle.
The Vehicle Identification Number is also
imprinted on the:
²Vehicle Safety Certification Label.
²Frame rail.
To protect the consumer from theft and possible
fraud the manufacturer is required to include a
Check Digit at the ninth position of the Vehicle Iden-
tification Number. The check digit is used by the
manufacturer and government agencies to verify the
authenticity of the vehicle and official documenta-
tion. The formula to use the check digit is not
released to the general public.
Fig. 4 VECI LABEL LOCATION
1 - RADIATOR SUPPORT
2 - VECI LABEL
Fig. 5 VIN NUMBER LOCATION
1 - A-PILLAR
2 - VIN CODE PLATE
8 INTRODUCTIONKJ

VEHICLE IDENTIFICATION NUMBER DECODING CHART
POSITION INTERPRETATION CODE = DESCRIPTION
1 Country of Origin 1 = United States
2 Make J = Jeep
3 Vehicle Type 4 = MPV W/O Side Airbags.
8 = MPV With Side Airbags.
4 Gross Vehicle Weight Rating F = 4001 - 5000 lbs.
G = 5001 - 6000 lbs.
5 Vehicle Line K = Liberty 4X2 (LHD)
L = Liberty 4X4 (LHD)
M = Cherokee 4X4 (RHD)
6 Series 3 = Liberty Renegade
4 = Liberty Sport/Cherokee Sport
5 = Liberty Limited/Cherokee Limited
7 Body Style 8 = Sport Utility - 4 Door
8 Engine K = 3.7L 6 cyl MPI Gasoline
1 = 2.4L 4 cyl MPI Gasoline
7 = 2.5L 4 cyl Diesel
9 Check Digit 0 through 9 or X
10 Model Year 2=2002
11 Assembly Plant W = Toledo North Assembly Plant
12 thru 17 Vehicle Build Sequence
VEHICLE SAFETY
CERTIFICATION LABEL
DESCRIPTION
A vehicle safety certification label (Fig. 6) is
attached to every DaimlerChrysler Corporation vehi-
cle. The label certifies that the vehicle conforms to all
applicable Federal Motor Vehicle Safety Standards.
The label also lists:
²Month and year of vehicle manufacture.
²Gross Vehicle Weight Rating (GVWR). The gross
front and rear axle weight ratings (GAWR's) arebased on a minimum rim size and maximum cold tire
inflation pressure.
²Vehicle Identification Number (VIN).
²Type of vehicle.
²Bar code.
²Month, Day and Hour (MDH) of final assembly.
²Paint and Trim codes.
²Country of origin.
The label is located above the door hinge on the
driver-side A-pillar.
Fig. 6 Vehicle Safety Certification LabelÐTypical
KJINTRODUCTION 9
VEHICLE IDENTIFICATION NUMBER (Continued)

LUBRICATION & MAINTENANCE
TABLE OF CONTENTS
page page
INTERNATIONAL SYMBOLS
DESCRIPTION Ð INTERNATIONAL SYMBOLS . . 1
FLUID TYPES
DESCRIPTION
DESCRIPTION - FLUID TYPES............1
DESCRIPTION - AXLE...................2
DESCRIPTION - MANUAL TRANSMISSION . . . 2
DESCRIPTION - AUTOMATIC
TRANSMISSION FLUID..................2
DESCRIPTION - TRANSFER CASE - NV231 . . 3
DESCRIPTION - TRANSFER CASE - NV242 . . 3
DESCRIPTION - ENGINE COOLANT........3
OPERATION - AUTOMATIC TRANSMISSION
FLUID...............................4FLUID CAPACITIES
SPECIFICATIONS - FLUID CAPACITIES.......4
FLUID FILL/CHECK LOCATIONS
DESCRIPTION..........................5
MAINTENANCE SCHEDULES
DESCRIPTION..........................5
HOISTING
STANDARD PROCEDURE - HOISTING
RECOMMENDATIONS...................5
JUMP STARTING
STANDARD PROCEDURE - JUMP STARTING
PROCEDURE.........................6
TOWING
STANDARD PROCEDURE - TOWING.........6
INTERNATIONAL SYMBOLS
DESCRIPTION Ð INTERNATIONAL SYMBOLS
DaimlerChrysler Corporation uses international
symbols to identify engine compartment lubricant
and fluid inspection and fill locations (Fig. 1).
FLUID TYPES
DESCRIPTION
DESCRIPTION - FLUID TYPES
When service is required, DaimlerChrysler Corpo-
ration recommends that only Mopartbrand parts,
lubricants and chemicals be used. Mopartprovides
the best engineered products for servicing
DaimlerChrysler Corporation vehicles.
Only lubricants bearing designations defined by
the following organization should be used to service a
Chrysler Corporation vehicle.
²Society of Automotive Engineers (SAE)
²American Petroleum Institute (API) (Fig. 2)
²National Lubricating Grease Institute (NLGI)
(Fig. 3)
SAE VISCOSITY RATING
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. These are specified with a dual
SAE viscosity grade which indicates the cold-to-hot
temperature viscosity range. Example SAE 5W-30 =
multigrade engine oil.
DaimlerChrysler Corporation only recommends
multigrade engine oils.
Fig. 1 International Symbols
KJLUBRICATION & MAINTENANCE 0 - 1

API QUALITY CLASSIFICATION
This symbol (Fig. 2) on the front of an oil container
means that the oil has been certified by the Ameri-
can Petroleum Institute (API) to meet all the lubri-
cation requirements specified by DaimlerChrysler
Corporation.
GEAR LUBRICANTS
SAE ratings also apply to multigrade gear lubri-
cants. In addition, API classification defines the
lubricants usage. Such as API GL-5 and SAE 75W-
90.
LUBRICANTS AND GREASES
Lubricating grease is rated for quality and usage
by the NLGI. All approved products have the NLGI
symbol (Fig. 3) on the label. At the bottom NLGI
symbol is the usage and quality identification letters.
Wheel bearing lubricant is identified by the letter
ªGº. Chassis lubricant is identified by the latter ªLº.
The letter following the usage letter indicates the
quality of the lubricant. The following symbols indi-
cate the highest quality.
SPECIALIZED LUBRICANTS AND OILS
Some maintenance or repair procedures may
require the use of specialized lubricants or oils. Con-
sult the appropriate sections in this manual for the
correct application of these lubricants.
DESCRIPTION - AXLE
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
Lubricants conforms to these specifications.
FRONT AXLE
²Lubricant for 186FIA (Model 30) axle is SAE
75W-140 SYNTHETIC.
REAR AXLE
²Lubricant for 198RBI (Model 35) axle is SAE
75W-140 SYNTHETIC.
²Lubricant for 8 1/4 axle is a thermally stable
SAE 75W-90. For trailer tow or heavy duty applica-
tions the lubricant should be replaced with SAE
75W-140 SYNTHETIC.
NOTE: Trac-lokTequipped axles require a friction
modifier be added to the lubricant.
CAUTION: If axle is submerged in water, lubricant
must be replaced immediately to avoid possible
premature axle failure.
DESCRIPTION - MANUAL TRANSMISSION
Mopartmanual transmission fluid is the lubricant
recommended for the NV1500 and the NV3550 trans-
missions.
DESCRIPTION - AUTOMATIC TRANSMISSION
FLUID
NOTE: Refer to the maintenance schedules in this
group for the recommended maintenance (fluid/filter
change) intervals for this transmission.
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
Fig. 2 API Symbol
Fig. 3 NLGI Symbol
1 - WHEEL BEARINGS
2 - CHASSIS LUBRICATION
3 - CHASSIS AND WHEEL BEARINGS
0 - 2 LUBRICATION & MAINTENANCEKJ
FLUID TYPES (Continued)

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

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)

(10) Start the engine and re-check for vibration. If
there is little or no change in vibration, move the
clamp to one of the other three positions. Repeat the
vibration test.
(11) If there is no difference in vibration at the
other positions, the source of the vibration may not
be propeller shaft.
(12) If the vibration decreased, install a second
clamp (Fig. 2) and repeat the test.
(13) If the additional clamp causes an additional
vibration, separate the clamps (1/4 inch above and
below the mark). Repeat the vibration test (Fig. 3).
(14) Increase distance between the clamp screws
and repeat the test until the amount of vibration is
at the lowest level. Bend the slack end of the clamps
so the screws will not loosen.
(15) If the vibration remains unacceptable, apply
the same steps to the front end of the propeller shaft.
(16) Install the wheel and tires. Lower the vehicle.RUNOUT
(1) Remove dirt, rust, paint and undercoating from
the propeller shaft surface where the dial indicator
will contact the shaft.
(2) The dial indicator must be installed perpendic-
ular to the shaft surface.
(3) Measure runout at the center and ends of the
shaft sufficiently far away from weld areas to ensure
that the effects of the weld process will not enter into
the measurements.
(4) Refer to Runout Specifications chart.
(5) If the propeller shaft runout is out of specifica-
tion, remove the propeller shaft, index the shaft 180É,
and re-install the propeller shaft. Measure shaft
runout again.
(6) If the propeller shaft runout is now within
specifications, mark the shaft and yokes for proper
orientation.
(7) If the propeller shaft runout is not within spec-
ifications, verify that the runout of the transmission/
transfer case and axle are within specifications.
Correct as necessary and re-measure propeller shaft
runout.
(8) Replace the propeller shaft if the runout still
exceeds the limits.
RUNOUT SPECIFICATIONS
Front of Shaft 0.020 in. (0.50 mm)
Center of Shaft 0.025 in. (0.63 mm)
Rear of Shaft 0.020 in. (0.50 mm)
note:
Measure front/rear runout approximately 3 inches (76
mm) from the weld seam at each end of the shaft
tube for tube lengths over 30 inches. For tube lengths
under 30 inches, the maximum allowed runout is
0.020 in. (0.50 mm) for the full length of the tube.
STANDARD PROCEDURES - PROPELLER
SHAFT ANGLE
The procedure applies to both the front propeller
shafts and the rear propeller shaft. To obtain the
front (output) angle on the C/V front propeller shaft,
the inclinometer is placed on the machined ring of
the pinion flange. To obtain the propeller shaft angle
measurement on the C/V front propeller shaft, the
inclinometer is placed on the propeller shaft tube.
(1) Raise and support the vehicle at the axles as
level as possible. Allow the wheels and propeller
shaft to turn.
(2) Remove any external bearing snap rings from
universal joint if equipped, so the inclinometer base
will sits flat.
Fig. 2 TWO CLAMPS AT SAME POSITION
Fig. 3 CLAMPS SEPARATED
1 - ó INCH
KJPROPELLER SHAFT 3 - 3
PROPELLER SHAFT (Continued)

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)

The Trac-lokŸ design provides the differential
action needed for turning corners and for driving
straight ahead during periods of unequal traction.
When one wheel looses traction, the clutch packs
transfer additional torque to the wheel having the
most traction. Trac-lokŸ differentials resist wheel
spin on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided 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 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 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.
KJREAR AXLE - 198RBI 3 - 51
REAR AXLE - 198RBI (Continued)