towing capacity JEEP CHEROKEE 1994 Service Repair Manual

AXLE NOISE/VIBRATION DIAGNOSIS
INDEX
page page
Driveline Snap........................... 17
Gear and Bearing Noise................... 16
General Information....................... 16Low Speed Knock........................ 17
Vibration............................... 17
GENERAL INFORMATION
Axle bearing problem conditions are usually caused
by:
²Insufficient or incorrect lubricant
²Foreign matter/water contamination
²Incorrect bearing preload torque adjustment
²Incorrect backlash (to tight)
When serviced, the bearings must be cleaned thor-
oughly. They should be dried with lint-free shop tow-
els.Never dry bearings with compressed air.
This will overheat them and brinell the bearing
surfaces. This will result in noisy operation after
repair.
Axle gear problem conditions are usually the result
of:
²Insufficient lubrication
²Incorrect or contaminated lubricant
²Overloading (excessive engine torque) or exceeding
vehicle weight capacity
²Incorrect clearance or backlash adjustment
Insufficient lubrication is usually the result of a
housing cover leak. It can also be from worn axle
shaft or pinion gear seals. Check for cracks or porous
areas in the housing or tubes.
Using the wrong lubricant will cause overheating
and gear failure. Gear tooth cracking and bearing
spalling are indicators of this.
Axle component breakage is most often the result
of:
²Severe overloading
²Insufficient lubricant
²Incorrect lubricant
²Improperly tightened components
Overloading occurs when towing heavier than rec-
ommended loads. Component breakage can occur
when the wheels are spun excessively. Incorrect lu-
bricant quantity contributes to breakage. Loose dif-
ferential components can also cause breakage.
Incorrect bearing preload or gear backlash will not
result in component breakage. Mis-adjustment will
produce enough noise to cause service repair before a
failure occurs. If a mis-adjustment condition is not
corrected, component failure can result.
Excessive bearing preload may not be noisy. This
condition will cause high temperature which can re-
sult in bearing failure.
GEAR AND BEARING NOISE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant. Incorrect backlash, tooth contact, or worn/dam-
aged gears can cause noise.
Gear noise usually happens at a specific speed
range. The range is 30 to 40 mph, or above 50 mph.
The noise can also occur during a specific type of
driving condition. These conditions are acceleration,
deceleration, coast, or constant load.
When road testing, accelerate 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, check for insuf-
ficient lubricant. Incorrect ring gear backlash, or
gear damage can cause noise changes.
Differential side and pinion gears can be checked
by turning the vehicle. They usually do not cause
noise in straight-ahead driving. These gears are
loaded during vehicle turns. If noise does occur dur-
ing vehicle turns, the side or pinion gears could be
worn or damaged. A worn pinion gear mate shaft can
also cause a snapping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion gear bear-
ings can all produce noise when worn or damaged.
Bearing noise can be either a whining, or a growling
sound.
Pinion gear bearings have a constant-pitch noise.
This noise changes only with vehicle speed. Pinion
bearing noise will be higher because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs the pinion rear bearing is
the source of the noise. If the bearing noise is heard
during a coast, front bearing is the source.
Worn, damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing. The pitch of differential
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
2 - 16 FRONT SUSPENSION AND AXLEJ

TEMPERATURE SENSOR TEST, ENGINE
COOLANT; FUEL SYSTEM..............14-43
TEMPERATURE SENSOR TEST, ENGINE
COOLANT; IGNITION SYSTEMS..........8D-12
TEMPERATURE SENSOR TEST, INTAKE
AIR ...............................14-43
TEMPERATURE SENSOR TEST, INTAKE
MANIFOLD AIR......................8D-14
TENSION, BELT.......................8B-10
TENSION, DRIVE BELT...............7-33,7-38
TENSIONÐRIGHT HAND DRIVE
(RHD),BELT..........................7-34
TENSION SPECIFICATIONS, BELT...........7-34
TENSIONER REPLACEMENT (XJ), PARKING
BRAKE CABLE........................5-61
TENSIONERÐXJ MODELS, AUTOMATIC
BELT ...............................7-36
TERMINAL ASSEMBLY REPLACEMENT,
CONNECTOR.........................8W-5
TERMINAL REPLACEMENT...............8W-5
TEST, A/C PERFORMANCE................24-8
TEST, ACTUATOR MOTOR STALL...........8P-6
TEST, AIR PRESSURE...................21-73
TEST, ANALYZING THE ROAD.............21-70
TEST, BATTERY LOAD...................8A-4
TEST, BATTERY OPEN CIRCUIT VOLTAGE....8A-3
TEST, CAMSHAFT POSITION SENSOR;
FUEL SYSTEM.......................14-43
TEST, CAMSHAFT POSITION SENSOR;
IGNITION SYSTEMS...................8D-8
TEST, CONVERTER STALL...............21-72
TEST, CRANKSHAFT POSITION SENSOR;
FUEL SYSTEM.......................14-44
TEST, CRANKSHAFT POSITION SENSOR;
IGNITION SYSTEMS...................8D-9
TEST, CYLINDER COMBUSTION
PRESSURE LEAKAGE...................9-6
TEST, CYLINDER COMBUSTION
PRESSURE LEAKAGE DIAGNOSIS..........9-6
TEST, CYLINDER COMPRESSION PRESSURE . . 9-5
TEST, ENGINE COOLANT TEMPERATURE
SENSOR......................8D-12,14-43
TEST, EXTENDED IDLE SWITCH...........14-45
TEST, FUEL PRESSURE LEAK DOWN........14-7
TEST, FUEL PUMP CAPACITY..............14-7
TEST, FUEL SYSTEM PRESSURE......14-5,14-48
TEST, HYDRAULIC PRESSURE......21-71,21-168
TEST, HYDROMETER....................8A-3
TEST, IDLE AIR CONTROL MOTOR........14-46
TEST, INJECTOR.......................14-48
TEST, INTAKE AIR TEMPERATURE SENSOR . . 8D-14,
14-43
TEST, MANIFOLD ABSOLUTE PRESSURE
(MAP) SENSOR.................8D-14,14-44
TEST, MANUAL SHIFTING...............21-168
TEST, MASTER CYLINDER/POWER
BOOSTER............................5-11
TEST, OXYGEN SENSOR (O2S)
HEATING ELEMENT...................14-45
TEST, POWER BOOSTER CHECK VALVE......5-11
TEST, POWER BOOSTER VACUUM..........5-12
TEST PROCEDURES, BATTERY............8A-2
TEST PROCEDURES ON VEHICLE,
ENGINE STARTER MOTOR..............8A-9
TEST PROCEDURES ON VEHICLE,
GENERATOR........................8A-14
TEST, PUMP PRESSURE.................19-3
TEST, REAR WINDOW DEFOGGER GRID.....8N-1
TEST, REFRIGERANT LEAK................24-8
TEST, ROAD; TRANSMISSION AND
TRANSFER CASE.....................21-70
TEST, ROAD; VEHICLE SPEED CONTROL
SYSTEM............................8H-5
TEST SPECIFICATIONS, 30RH/32RH
PRESSURE........................21-323
TEST, SPEED CONTROL SWITCH (TURN
SIGNAL LEVER)......................8H-7
TEST, STARTER MOTOR RELAY...........14-48
TEST, STARTING SYSTEM COLD
CRANKING...........................8A-9
TEST, STOP LAMP SPEED CONTROL
SWITCH
............................8H-7
TEST, THROTTLE POSITION SENSOR
......8D-18
TEST, THROTTLE POSITION SENSOR
(TPS)
..............................14-45
TEST, TIME LAG
......................21-169TEST, TORQUE CONVERTER CLUTCH
RELAY.............................14-45
TEST, TORQUE CONVERTER STALL.......21-169
TEST, VACUUM SUPPLY.................8H-7
TEST, VEHICLE SPEED SENSOR......8H-5,14-45
TESTING, AUTOMATIC SHUTDOWN
(ASD) RELAY........................14-43
TESTING COOLING SYSTEM FOR LEAKS.....7-18
TESTING, FUEL PUMP RELAY............14-44
TESTING GENERAL INFORMATION,
BATTERY............................8A-3
TESTING, IGNITION SWITCH.............8D-30
TESTING, POWER MIRROR SWITCH........8T-2
TESTING, REAR WIPER/WASHER
SWITCH.......................8K-7,8K-14
TESTING, SWITCH; POWER SEATS.........8R-2
TESTING, SWITCH; POWER WINDOWS......8S-5
TESTING, SWITCH; REAR WINDOW
DEFOGGER..........................8N-2
TESTING, TRANSMISSION COOLER FLOW . . 21-106
TESTING, WIPER SWITCH...............8K-19
TESTS - (VOLTAGE DROP METHOD),
STARTER FEED CIRCUIT................8A-9
TESTS, ANTENNA.......................8F-9
TESTS AT POWERTRAIN CONTROL
MODULE, ELECTRICAL.................8H-6
TESTS AT SERVO, ELECTRICAL............8H-5
TESTS, COMPRESSOR VALVE PLATEÐ
LEAK...............................24-8
TESTS, IGNITION SWITCH CONTINUITY....8D-31
TESTS, OXYGEN SENSOR...............8D-19
TESTS, STARTER CONTROL CIRCUIT......8A-11
TESTS, VEHICLE SPEED CONTROL
SYSTEM............................8H-5
TESTS, WATER PUMP....................7-9
THERMOMETER AND SENSOR SYSTEM
REPAIR PROCEDURES.................8C-6
THERMOSTAT..........................7-13
THERMOSTAT, TEMPERATURE CONTROL . . . 24-35
THICKNESS, AW-4 CLUTCH DISC AND
PLATE ............................21-325
THICKNESS, DISC BRAKE ROTOR..........5-31
THICKNESS VARIATION, DISC BRAKE
ROTOR.............................5-31
THIRD GEAR (CONVERTER CLUTCH
ENGAGED), HYDRAULIC FLOW IN.......21-90
THIRD GEAR, HYDRAULIC FLOW IN D
RANGE.............................21-89
THREAD NOTATIONÐSAE AND METRIC . . INTRO.-9
THREADS, REPAIR DAMAGED OR WORN.....9-4
THROTTLE 3-2 DOWNSHIFT, HYDRAULIC
FLOW DURING FULL..................21-92
THROTTLE 3-2 DOWNSHIFT, HYDRAULIC
FLOW DURING PART..................21-91
THROTTLE BODY; FUEL SYSTEM.....14-29,14-59
THROTTLE CABLE.....................14-16
THROTTLE CABLE, ACCELERATOR PEDAL . . 14-16,
14-54
THROTTLE CABLE ADJUSTMENT,
TRANSMISSION.....................21-185
THROTTLE CABLE ADJUSTMENT,
TRANSMISSION......................21-98
THROTTLE CABLE REPLACEMENT,
TRANSMISSION.....................21-184
THROTTLE POSITION SENSOR............8D-6
THROTTLE POSITION SENSOR TEST.......8D-18
THROTTLE POSITION SENSOR (TPS);
FUEL SYSTEM.......................14-59
THROTTLE POSITION SENSOR (TPS);
IGNITION SYSTEMS..................8D-29
THROTTLE POSITION SENSOR (TPS)
SERVICE..........................21-184
THROTTLE POSITION SENSOR (TPS)
TEST..............................14-45
THROTTLE POSITION SENSOR (TPS)Ð
PCM INPUT.........................14-23
THROTTLE VALVE CABLE ADJUSTMENT,
TRANSMISSION......................21-70
TIE ROD ........................19-14,19-17
TIGHTENING, WHEEL NUT............5-32,5-37
TILT STEERING COLUMN................19-59
TIME LAG TEST
......................21-169
TIMING CASE COVER
................9-27,9-67
TIMING CASE COVER OIL SEAL
REPLACEMENT
...................9-26,9-67
TIMING CHAIN AND SPROCKETS
......9-28,9-68TIMING, IGNITION.....................8D-14
TIMING, VALVE.....................9-26,9-66
TIPS, TRANSMISSION ASSEMBLY........21-146
TIRE AND WHEEL BALANCE..............22-6
TIRE AND WHEEL RUNOUT...............22-8
TIRE CARRIER, EXTERNAL SPARE/WHEEL . 23-172
TIRE INFLATION PRESSURE LABEL.....INTRO.-3
TIRE INFLATION PRESSURES.............22-2
TIRE NOISE OR VIBRATION...............22-4
TIRE WEAR PATTERNS..................22-4
TIRES; LUBRICATION AND MAINTENANCE....0-34
TIRES................................22-1
TIRES, CLEANING OF....................22-2
TIRES, REPLACEMENT...................22-2
TIRE/WHEEL HOLDDOWN AND FLOOR
BRACKETS.........................23-128
TOOL, DRB SCAN; COOLING SYSTEM........7-5
TOOL, DRB SCAN; EMISSION CONTROL
SYSTEMS...........................25-2
TOOL, DRB SCAN; FUEL SYSTEM.........14-51
TOOL, DRB SCAN; IGNITION SYSTEMS.....8D-10
TOP REPAIR, HARD...................23-165
TOP ROOF VENT......................23-165
TOP SERVICE............23-164,23-166,23-167
TORQUE; COOLING SYSTEM..............7-39
TORQUE; FUEL SYSTEM................14-62
TORQUE; IGNITION SYSTEMS............8D-33
TORQUE, COLLISION DAMAGE............13-1
TORQUE CONVERSION..............INTRO.-10
TORQUE CONVERTER; TRANSMISSION
AND TRANSFER CASE...........21-66,21-158
TORQUE CONVERTER CLUTCH RELAY......14-60
TORQUE CONVERTER CLUTCH RELAY
TEST..............................14-45
TORQUE CONVERTER CLUTCH RELAYÐ
PCM OUTPUT.......................14-27
TORQUE CONVERTER INSTALLATION,
TRANSMISSION.....................21-190
TORQUE CONVERTER REMOVAL,
TRANSMISSION.....................21-189
TORQUE CONVERTER STALL TEST.......21-169
TORQUE CONVERTER STATOR CLUTCH
INSPECTION.......................21-189
TORQUE SPECIFICATIONS, 30RH/32RH....21-323
TORQUE SPECIFICATIONSÐ AX 15
MANUAL TRANSMISSION.............21-320
TORQUE SPECIFICATIONSÐACCESSORIES . 23-208
TORQUE SPECIFICATIONS, AW-4
.........21-331
TORQUE SPECIFICATIONS, BATTERY
.......8B-10
TORQUE SPECIFICATIONS; BATTERY/
STARTER/GENERATOR SERVICE
.........8B-12
TORQUE SPECIFICATIONS, BRAKE
..........5-67
TORQUE SPECIFICATIONS; CLUTCH
........6-17
TORQUE SPECIFICATIONS; ELECTRICAL
.....8A-8
TORQUE SPECIFICATIONS; ENGINES
....9-49,9-89
TORQUE SPECIFICATIONS; EXHAUST
SYSTEM AND INTAKE MANIFOLD
........11-10
TORQUE SPECIFICATIONS; FRONT
SUSPENSION AND AXLE
................2-47
TORQUE SPECIFICATIONS; HEATING AND
AIR CONDITIONING
...................24-45
TORQUE SPECIFICATIONS; HORNS
.........8G-3
TORQUE SPECIFICATIONS;
INTRODUCTION
...................INTRO.-8
TORQUE SPECIFICATIONS, NP231/NP242
. . 21-331
TORQUE SPECIFICATIONS; PROPELLER
SHAFTS
............................16-14
TORQUE SPECIFICATIONS; REAR
SUSPENSION AND AXLES
...............3-50
TORQUE SPECIFICATIONS, STARTER
MOTOR
............................8B-11
TORQUE SPECIFICATIONS; STEERING
......19-73
TORQUE SPECIFICATIONS XJ
.............8K-7
TORQUE SPECIFICATIONSÐXJ VEHICLES
. . 23-207
TORQUE VALUES, STANDARD
.........INTRO.-9
TOW HOOKÐXJ VEHICLES, REAR
.........23-87
TOW HOOKS
..........................13-14
TOW HOOKS, FRONT
....................13-5
TOWING, JUMP STARTING, HOISTING
.......0-7
TOWING RECOMMENDATIONS
..............0-8
TRACK BAR
....................2-10,2-13,3-6
TRACKS, BUCKET SEAT PLATFORM
.......23-105
TRAC-LOK DIFFERENTIAL
................3-44
JINDEX23
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