1995 JEEP CHEROKEE torque

STANDARD DIFFERENTIAL OPERATION
The differential gear system divides the torque be-
tween the axle shafts. It allows the axle shafts to ro-
tate at different speeds when turning corners.
Each differential side gear is splined to an axle
shaft. The pinion gears are mounted on a pinion
mate shaft and are free to rotate on the shaft. The
pinion gear is fitted in a bore in the differential case
and is positioned at a right angle to the axle shafts.
In operation, power flow occurs as follows:
²The pinion gear rotates the ring gear²The ring gear (bolted to the differential case) ro-
tates the case
²The differential pinion gears (mounted on the pin-
ion mate shaft in the case) rotate the side gears
²The side gears (splined to the axle shafts) rotate
the 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. 3).
When turning corners, the outside wheel must travel
a greater distance than the inside wheel in order 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 al-
lows the axle shafts to turn at unequal speeds (Fig. 4).
In this instance, the input torque applied to the pinion
gears is not divided equally. The pinion gears now ro-
tate 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.
Fig. 4 Differential OperationÐOn Turns
Fig. 1 Model 35 Differential Cover
Fig. 2 8 1/4 Differential Cover
Fig. 3 Differential OperationÐStraight-Ahead Driving
3 - 2 REAR SUSPENSION AND AXLESJ

XJ SUSPENSION
INDEX
page page
Leaf Spring............................... 4
Leaf Spring Eye Bushing Replacement.......... 5
Shock Absorber........................... 4Spring and Shock Diagnosis.................. 3
Stabilizer Bar............................. 5
SPRING AND SHOCK DIAGNOSIS
A noise from the shock absorber or spring bushings
can be produced if movement between the rubber
bushings and the metal occurs. This noise can usu-
ally be stopped by tightening the nuts. If the noise
persists, inspect for damaged and worn bushings. Re-
pair as necessary.
The shock absorbers are not refillable or adjust-
able. If a malfunction occurs, the shock absorber
must be replaced. To test a shock absorber, hold it in
an upright position and force the piston into and out
of the cylinder four or five times. The action through-
out each stroke should be smooth and even.
The spring eye and shock absorber bushings do not
require any type of lubrication.Do not attempt to
stop spring bushing noise by lubricating them.Grease and mineral oil-base lubricants will de-
teriorate the bushing rubber.
If the vehicle is used for severe, off-road operation,
the springs should be examined regularly. Check for
broken and shifted components.
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.
SPRING AND SHOCK ABSORBER DIAGNOSIS
JREAR SUSPENSION AND AXLES 3 - 3

SHOCK ABSORBER
REMOVAL
(1) Remove the shock absorber upper bolts from the
frame bracket (Fig. 1).
(2) Remove the lower attaching nut and washer
from the bracket stud. Remove the shock absorber.
INSTALLATION
(1) Install the shock absorber lower eye on the
spring bracket stud. Install the shock absorber and
upper bolts on the frame bracket (Fig. 1).
(2) Tighten the lower nut to 62 Nzm (46 ft. lbs.)
torque.
(3) Tighten the upper bolts to 23 Nzm (17 ft. lbs.)
torque.
LEAF SPRING
REMOVAL
(1) Raise vehicle at frame.
(2) Remove the wheel and tire assemblies.
(3) Support axle with hydraulic jack to relieve axle
weight.
(4) Disconnect the shock absorber from the axle
bracket or the spring bracket (Fig. 1).
(5) Disconnect the stabilizer bar link from the
spring bracket stud.(6) Remove nuts, U-bolts and spring bracket from
axle (Fig. 1).
(7) Remove nut and bolt attaching spring front eye
to shackle (Fig. 1).
(8) Remove nut and bolt from spring rear eye (Fig.
1).
(9) Remove spring from vehicle.
INSTALLATION
(1) Position the spring front eye in the bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(2) Position the rear eye in the shackle bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(3) Position the axle. Install the spring bracket,
U-bolts and nuts (Fig. 1). Tighten the nuts to 70 Nzm
(52 ft. lbs.) torque.
(4) Connect the stabilizer bar link to the spring
bracket.
(5) Connect the shock absorber to the axle bracket
or spring bracket.
(6) Remove the hydraulic jack.
(7) Lower the vehicle.
(8) Tighten the spring front eye attaching bolts to
148 Nzm (109 ft. lbs.) torque.
(9) Tighten the spring rear eye attaching bolts to
108 Nzm (80 ft. lbs.) torque.
Fig. 1 Spring & Shock AbsorberÐXJ Vehicles
3 - 4 REAR SUSPENSION AND AXLESJ

LEAF SPRING EYE BUSHING REPLACEMENT
(1) Assemble tools shown (Fig. 2). Tighten the nut
located at the socket wrench end of the threaded rod
until the bushing is forced out.
(2) Assemble and align the bushing installation
tools.
(3) Align the bushing with the spring eye. Tighten
the nut located at the socket wrench end of the
threaded rod. Tighten until the bushing is forced into
the spring eye.
The bushing must be centered in the spring
eye. The ends of the bushing must be flush or
slightly recessed within the end surfaces of the
spring eye.
STABILIZER BAR
REMOVAL
(1) Raise and support the vehicle.
(2) Disconnect stabilizer bar links from spring
brackets (Fig. 3).
(3) Disconnect the stabilizer bar brackets from the
frame rails. Remove the stabilizer bar and links.
INSTALLATION
(1) Position the stabilizer bar links at the spring
brackets (Fig. 3). Install the attaching bolts and nuts
and tighten to 74 Nzm (55 ft. lbs.) torque.
(2) Attach the stabilizer bar to the frame rail
brackets with the bolts. Tighten to 54 Nzm (40 ft.
lbs.).
(3) Remove the supports and lower the vehicle.
Fig. 2 Spring Eye Bushing Removal
Fig. 3 Stabilizer BarÐXJ Vehicles
JREAR SUSPENSION AND AXLES 3 - 5

YJ SUSPENSION
INDEX
page page
Leaf Spring............................... 7
Leaf Spring Eye Bushing Replacement.......... 7
Shock Absorber........................... 7Spring and Shock Diagnosis.................. 6
Track Bar................................ 8
SPRING AND SHOCK DIAGNOSIS
A noise from the shock absorber or spring bushings
can be produced if movement between the rubber
bushings and the metal occurs. This noise can usu-
ally be stopped by tightening the nuts. If the noise
persists, inspect for damaged and worn bushings. Re-
pair as necessary.
The shock absorbers are not refillable or adjust-
able. If a malfunction occurs, the shock absorber
must be replaced. To test a shock absorber, hold it in
an upright position and force the piston into and out
of the cylinder four or five times. The action through-
out each stroke should be smooth and even.
The spring eye and shock absorber bushings do not
require any type of lubrication.Do not attempt tostop spring bushing noise by lubricating them.
Grease and mineral oil-base lubricants will de-
teriorate the bushing rubber.
If the vehicle is used for severe, off-road operation,
the springs should be examined regularly. Check for
broken and shifted components.
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.
SPRING AND SHOCK ABSORBER DIAGNOSIS
3 - 6 REAR SUSPENSION AND AXLESJ

SHOCK ABSORBER
REMOVAL
(1) Remove the upper attaching nut and washer
from the frame bracket stud (Fig. 1).
(2) Remove the lower attaching nut, washers and
bolt from the axle bracket. Remove the shock ab-
sorber (Fig. 1).
INSTALLATION
(1) Position the shock upper eye on the frame
bracket stud. Install the washer and nut (Fig. 1).
(2) Position the shock lower eye in the axle shaft
tube bracket. Install the lower attaching bolt, wash-
ers and nut (Fig. 1).
(3) Tighten the upper and lower shock bolts to 61
Nzm (45 ft. lbs.) torque.
LEAF SPRING
REMOVAL
(1) Raise the vehicle at the frame.
(2) Use a hydraulic jack to relieve the axle weight.
(3) Remove the wheel and tire.
(4) Remove the nuts, the U-bolts and spring
bracket from the axle (Fig. 1).
(5) Remove the nut and bolt that attaches the
spring rear eye to the shackle (Fig. 1).
(6) Remove the nut and bolt from the spring front
eye (Fig. 1).
(7) Remove the spring from the vehicle.
INSTALLATION
(1) Position the spring front eye in the bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(2) Position the rear eye in the shackle bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(3) Align the rear spring center bolt with the locat-
ing hole in the rear axle spring pad.
(4) Lower the rear axle until it is completely sup-
ported by the spring.
Ensure that the spring center bolt is seated in
the axle spring pad locating hole. Realign the
center bolt with the locating hole, if necessary.
(5) Position the axle. Install the spring bracket, U-
bolts and nuts (Fig. 1). Tighten the U-bolt nuts to
122 Nzm (90 ft. lbs.) torque.
(6) Remove the hydraulic jack.
(7) Remove the support stands and lower the vehi-
cle.
(8) Tighten the spring shackle plate bolts and front
spring eye bolt to 135 Nzm (100 ft. lbs.) torque.
LEAF SPRING EYE BUSHING REPLACEMENT
(1) Assemble tools shown (Fig. 2). Tighten the nut
located at the socket wrench end of the threaded rod
until the bushing is forced out.
(2) Assemble and align the bushing installation
tools.
(3) Align the bushing with the spring eye and
tighten the nut located at the socket wrench end of
the threaded rod. Tighten until the bushing is forced
into the spring eye.
Fig. 1 Spring & Shock AbsorberÐYJ Vehicles
JREAR SUSPENSION AND AXLES 3 - 7

The bushing must be centered in the spring
eye. The ends of the bushing must be flush or
slightly recessed within the end surfaces of the
spring eye.
TRACK BAR
REMOVAL
(1) Raise the vehicle. Position a hydraulic jack un-
der the axle and raise the axle to relieve the springs
of axle weight.(2) Remove the fasteners that attach the track bar
to the frame bracket and axle bracket (Fig. 3).
(3) Remove the track bar from the vehicle.
INSTALLATION
(1) Position the ends of the track bar in the frame
and axle brackets (Fig. 3).
(2) Install and tighten the track bar attaching nuts
to 168 Nzm (125 ft. lbs.) torque.
(3) Remove the supports and lower the vehicle.
Fig. 2 Spring Eye Bushing Removal
Fig. 3 Track BarÐYJ Vehicles
3 - 8 REAR SUSPENSION AND AXLESJ

AXLE NOISE/VIBRATION DIAGNOSIS
INDEX
page page
Driveline Snap........................... 10
Gear and Bearing Noise..................... 9
General Information........................ 9
Limited Slip Differential..................... 10Low Speed Knock......................... 10
Rear Axle Alignment....................... 10
Vibration................................ 10
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 af-
ter 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.
JREAR SUSPENSION AND AXLES 3 - 9