transmission fluid JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

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)

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.
DESCRIPTION - TRANSFER CASE - NV231
Recommended lubricant for the NV231 transfer
case is MopartATF +4, type 9602, Automatic Trans-
mission Fluid.
DESCRIPTION - TRANSFER CASE - NV242
Recommended lubricant for the NV242 transfer
case is MopartATF+4, type 9602 Automatic Trans-
mission Fluid.
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equiva-
lent ethylene glycol base coolant with organic corro-
sion inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37ÉC (-35ÉF). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solu-
tion.
CAUTION: MoparTAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Mixing of
coolants other than specified (non-HOAT or other
HOAT), may result in engine damage that may not
be covered under the new vehicle warranty, and
decreased corrosion protection.
COOLANT PERFORMANCE
The required ethylene-glycol (antifreeze) and water
mixture depends upon climate and vehicle operating
conditions. The coolant performance of various mix-
tures follows:
Pure Water-Water can absorb more heat than a
mixture of water and ethylene-glycol. This is for pur-
pose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol-The corrosion
inhibiting additives in ethylene-glycol need the pres-
ence of water to dissolve. Without water, additives
form deposits in system. These act as insulation
causing temperature to rise to as high as 149ÉC
(300ÉF). This temperature is hot enough to melt plas-
tic and soften solder. The increased temperature can
result in engine detonation. In addition, 100 percent
ethylene-glycol freezes at -22ÉC (-8ÉF).
50/50 Ethylene-Glycol and Water-Is the recom-
mended mixture, it provides protection against freez-
ing to -37ÉC (-34ÉF). The antifreeze concentration
must alwaysbe a minimum of 44 percent, year-
round in all climates. If percentage is lower, engine
parts may be eroded by cavitation. Maximum protec-
tion against freezing is provided with a 68 percent
antifreeze concentration, which prevents freezing
down to -67.7ÉC (-90ÉF). A higher percentage will
freeze at a warmer temperature. Also, a higher per-
KJLUBRICATION & MAINTENANCE 0 - 3
FLUID TYPES (Continued)

centage of antifreeze can cause the engine to over-
heat because specific heat of antifreeze is lower than
that of water.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
OPERATION - AUTOMATIC TRANSMISSION
FLUID
The automatic transmission fluid is selected based
upon several qualities. The fluid must provide a high
level of protection for the internal components by
providing a lubricating film between adjacent metal
components. The fluid must also be thermally stable
so that it can maintain a consistent viscosity through
a large temperature range. If the viscosity stays con-
stant through the temperature range of operation,
transmission operation and shift feel will remain con-
sistent. Transmission fluid must also be a good con-
ductor of heat. The fluid must absorb heat from the
internal transmission components and transfer that
heat to the transmission case.
FLUID CAPACITIES
SPECIFICATIONS - FLUID CAPACITIES
DESCRIPTION SPECIFICATION
FUEL TANK 18.5 U.S. Gallons (70
Liters)****
ENGINE OIL
Engine Oil - with Filter -
2.4L2.4L (5.0 qts.)
Engine Oil - with Filter -
3.7L3.7L (5.0 qts.)
Engine Oil - With Filter -
2.5L Diesel6.5L (6.9 qts.)
ENGINE COOLANT
Cooling System - 2.4L 9.6L (10.1 qts.)
Cooling System - 3.7L 12.3L (13.0 qts.)
Cooling System - 2.5L
Diesel12.5L (13.2 qts.)
AUTOMATIC TRANSMISSION
Service Fill - 45RFE 4.73L (10.0 pts)
O-haul Fill - 45RFE 13.33L (28.0 pts)
Dry fill capacity Depending on type and size of
internal cooler, length and inside diameter of cooler
lines, or use of an auxiliary cooler, these figures may
vary. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC/FLUID - STANDARD PROCEDURE)
TRANSFER CASE
NV231 1.4L (2.95 pts.)
NV242 1.6L (3.4 pts.)
MANUAL TRANSMISSION
NV1500 (Approximate dry
fill or fill to bottom edge of
the fill plug hole.)2.28L (2.41 qts.)
NV3550 (Approximate dry
fill or fill to bottom edge of
fill plug hole.)2.28L (2.41 qts.)
FRONT AXLE
186 FIA (Model 30) 1.24L (41.9 fl. oz.)
REAR AXLE
198 RBI (Model 35) 1.78L (60.2 fl. oz.)*
8 1/4 2.08L (4.4 pts.)*
* When equipped with Trac-lok, include 4.0 ounces of
Friction Modifier.
****Nominal refill capacities are shown. A variation
may be observed from vehicle to vehicle due to
manufacturing tolerance and refill procedure.
0 - 4 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

HALF SHAFT
TABLE OF CONTENTS
page page
HALF SHAFT
CAUTION.............................10
DIAGNOSIS AND TESTING - HALF SHAFT....10
REMOVAL.............................10
INSTALLATION.........................11
SPECIFICATIONS
HALF SHAFT.........................11SPECIAL TOOLS.......................12
CV JOINT/BOOT-OUTER
REMOVAL.............................12
INSTALLATION.........................13
CV JOINT/BOOT-INNER
REMOVAL.............................15
INSTALLATION.........................17
HALF SHAFT
CAUTION
CAUTION:: Never grasp half shaft assembly by the
boots. This may cause the boot to pucker or crease
and reduce the service life of the boot.
Avoid over angulating or stroking the C/V joints
when handling the half shaft.
Half shafts exposed to battery acid, transmission
fluid, brake fluid, differential fluid or gasoline may
cause the boots to deteriorate.
DIAGNOSIS AND TESTING - HALF SHAFT
Check for grease at the inboard and outboard C/V
joint. This is a sign of boot or boot clamp damage.
NOISE AND/OR VIBRATION IN TURNS
A clicking noise or a vibration in turns could be
caused by a damaged outer C/V or inner tripod joint
seal boot or seal boot clamps. This will result in the
loss/contamination of the joint grease, resulting in
inadequate lubrication of the joint. Noise could also
be caused by another component of the vehicle com-
ing in contact with the half shafts.
CLUNKING NOISE DURING ACCELERATION
This noise may be a result of a damaged or worn
C/V joint. A torn boot or loose/missing clamp on the
inner/outer joint which has allowed the grease to be
lost will damage the C/V joint.
SHUDDER OR VIBRATION DURING ACCELERATION
This problem could be a result of a worn/damaged
inner tripod joint or a sticking tripod joint. Improper
wheel alignment may also cause a shudder or vibration.
VIBRATION AT HIGHWAY SPEEDS
This problem could be a result of out of balance
front tires or tire/wheel runout. Foreign material
(mud, etc.) packed on the backside of the wheel(s)
will also cause a vibration.
REMOVAL
(1) Raise and support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove half shaft hub nut.
(4) Remove stabilizer link (Fig. 1).
Fig. 1 STABILIZER BAR LINK
1 - STABILIZER BAR
2 - STABILIZER BAR LINK
3 - 10 HALF SHAFTKJ

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)

AXLE SHAFTS
REMOVAL
(1) Place the transmission in Neutral.
(2) Raise and support vehicle.
(3) Remove right wheel and tire and assembly.
(4) Remove right half shaft from vehicle.
(5) Remove snap ring from axle shaft.
(6) Assemble Remover 8420A onto the shaft (Fig.
25). Thread slid hammer into remover and remove
shaft.
(7) Slide axle shaft out of the axle tube.
NOTE: Use care to prevent damage to axle shaft
bearing and seal, which will remain in axle shaft
tube.
INSTALLATION
(1) Lubricate bearing bore and seal lip with gear
lubricant. Insert axle shaft through seal, bearing
(Fig. 26) and engage it into side gear splines.
NOTE: Use care to prevent shaft splines from dam-
aging axle shaft seal.
(2) Push on the axle shaft until the axle shaft
snap-ring passes through the side gear.
(3) Install right half shaft.
(4) Install right wheel and tire assembly.
(5) Check differential fluid level.
(6) Lower vehicle.
AXLE SHAFT SEALS
REMOVAL
(1) Remove half shaft.
(2) Remove axle shaft for right side seal removal.
(3) Remove shaft seal with Remover 7794-A and a
slide hammer (Fig. 27).
Fig. 25 AXLE SHAFT PULLER
1 - SNAP RING GROVE
2 - SLID HAMMER THREADS
3 - REMOVER BLOCKS
4 - REMOVER COLLAR
Fig. 26 AXLE SHAFT SEAL
1 - BEARING
2 - SEAL
Fig. 27 SHAFT SEAL REMOVER
1 - SHAFT SEAL
2 - REMOVER
KJFRONT AXLE - 186FIA 3 - 37

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)

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)