JEEP YJ 1995 Service And Workshop Manual

(2) Note any indication of drum/rotor overheating,
wheel dragging or the vehicle pulling to one side
when the brakes are applied.
(3) Evaluate any performance complaints received
from the owner/operator.
(4) Repair the brake system as necessary. Refer to
Group, 5 Brakes for additional information and ser-
vice procedures.
TIRES
RECOMMENDED MAINTENANCE
The general condition of the tires and the inflation
pressures should be inspected at the same time the
engine oil is changed and the oil filter is replaced.
In addition, the tires/wheels should be rotated at
the intervals described in the Maintenance Schedules
section of this group.
INSPECTION
Inspect the tires for excessive wear, damage, etc.
Test the tires for the recommended inflation pres-sure. Refer to the tire inflation pressure decal located
on the inside of the glove box door, and also to Group
22, Tires And Wheels.
ROTATION
Refer to Group 22, Tires And Wheels for the recom-
mended method of tire/wheel rotation for a Jeep ve-
hicle.
BODY COMPONENTS
LUBRICATION REQUIREMENTS
All Jeep operating mechanisms and linkages
should be lubricated when necessary. The door
weatherstrip seals should be lubricated to prolong
their life as well as to improve door sealing.
LUBRICANT SPECIFICATIONS
All applicable exterior and interior vehicle operat-
ing mechanisms should be:
²Inspected
²Cleaned
²Pivot/sliding contact areas on the mechanisms
should then be lubricated.
Multi-purpose NLGI GC-LB MOPAR Multi-Mileage
Lubricant or an equivalent, should be used to lubri-
cate the mechanisms. The door weatherstrip seals
should be lubricated with silicone lubricant spray.
Refer to the Body Lubricant Specifications chart be-
low for additional lubricant applications.
LUBRICATION
All pivoting and sliding contact areas, should be lu-
bricated periodically to ensure quiet, easy operation
and to protect against wear and corrosion. Areas in-
clude:
²Seat tracks.
²Door hinges/latches/strikers.
²Liftgate/tailgate/hood hinges (Fig. 11).
(1) As required, lubricate the body components
with the specified lubricants.
(2) Apply silicone lubricant to a cloth and wipe it
on door seals to avoid over-spray that can soil pas-
senger clothing.
(3) Before applying lubricant, the component
should be wiped clean. After lubrication, any excess
lubricant should be removed.
(4) The door lock cylinders should be lubricated 2
times each year (preferably autumn and spring):
²Spray a small amount of lock cylinder lubricant di-
rectly into the lock cylinder.
²Apply a small amount to the key and insert it into
the lock cylinder.
²Rotate it to the locked position and then back to
the unlocked position several times.
²Remove the key. Wipe the lubricant from it with a
clean cloth to avoid soiling of clothing.
Fig. 9 Park Brake Equalizer (XJ)ÐTypical
Fig. 10 Park Brake Equalizer (YJ)ÐTypical
0 - 32 LUBRICATION AND MAINTENANCEJ

(5) Extra close attention should also be given to
the hood latch components to ensure proper function-
ing.
HEADLAMPS
MAINTENANCE SCHEDULE
Every six months check the headlamp beams to en-
sure that the headlamp beams are correctly posi-
tioned.
AIM ADJUSTMENT
Refer to Group 8L, Lamps for headlamp aim ad-
justment procedures.
SPEEDOMETER CABLE
SERVICE INFORMATION
Speedometer cable lubrication is not necessary. For
service information involving noisy cables, refer to
Group 8E, Instrument Panel and Gauges.
BODY LUBRICANT SPECIFICATIONS
Fig. 11 Hood Hinge LubricationÐXJ Vehicles
JLUBRICATION AND MAINTENANCE 0 - 33

FRONT SUSPENSION AND AXLE
CONTENTS
page page
AXLE NOISE/VIBRATION DIAGNOSIS........ 18
AXLE SPECIFICATIONS................... 49
FRONT WHEEL ALIGNMENT................ 5
GENERAL INFORMATION.................. 1MODEL 30 AXLE AND TUBE AXLE (2WD).... 22
TORQUE SPECIFICATIONS................ 49
XJ FRONT SUSPENSION.................. 11
YJ FRONT SUSPENSION.................. 15
GENERAL INFORMATION
FRONT SUSPENSION
XJ VEHICLES
The XJ front suspension is a link/coil design. This
suspension is use on Left Hand Drive (LHD) and
Right Hand Drive (RHD) vehicles. It is comprised of
(Fig. 1);
²Drive axle (4WD), tube axle (2WD)²Track bar
²Stabilizer bar
²Upper and lower suspension arms
²Coil springs
²Dual-action shock absorbers
²Jounce bumpers
The link/coil suspension allows each wheel to adapt
to different road surfaces without greatly affecting
Fig. 1 XJ Front Suspension (LHD)
JFRONT SUSPENSION AND AXLE 2 - 1

the opposite wheel. Wheels are attached to a hub/
bearings which bolts to the knuckles. The hub/bear-
ing is not serviceable and is replaced as a unit.
Steering knuckles pivot on replaceable ball studs at-
tached to the axle tube yokes.
The upper and lower suspension arms are different
lengths, with bushings at both ends. They bolt the
axle assembly to the body. The lower arms uses
shims at the body mount to allow for adjustment of
caster and drive shaft pinion angle. The suspension
arm travel is limited through the use of jounce
bumpers in compression and shocks absorbers in re-
bound.
Suspension components which use rubber bushings
should be tightened at vehicle ride height. This will
prevent premature failure of the bushing and main-
tain ride comfort. Bushings must never be lubricated.
The coil springs control ride quality and maintain
proper ride height. The coil springs mount up in the
fender shield which is part of the unitized body
bracket. A rubber isolator is located between the top
of the spring and the frame. The bottom of the spring
seats on a axle pad and is retained with a clip.
The shock absorbers dampen jounce and rebound of
the vehicle over various road conditions. The top of
the shock absorbers are bolted to the body. The bot-
tom of the shocks are bolted to the axle spring
bracket.
The stabilizer bar is used to minimize vehicle body
roll during turns. The spring steel bar helps to con-
trol the vehicle body in relationship to the suspen-
sion. The bar extends across the front underside of
the chassis and connects to the body rails. Links are
connected from the bar to the axle brackets. Stabi-
lizer bar mounts are isolated by rubber bushings.
The track bar is used to minimize front axle side-
to-side movement. The bar is attached to a frame rail
bracket with a ball stud and isolated with a bushing
at the axle bracket.
TUBE AXLE (2WD VEHICLES)
The front axle used on two-wheel drive vehicles is
a one-piece, tubular axle (Fig. 2). The tubular axle
mounts in the same bracketry as the four-wheel
drive axle.
The steering knuckles and hub bearing assemblies
are the same as used on the Model 30 drive axle.
YJ VEHICLES
The Wrangler (YJ) front suspension is leaf spring
design comprised of (Fig. 3);
²Drive axle
²Track bar
²Stabilizer bar
²Leaf springs
²Dual-action shock absorbers
²Jounce bumpers (used to limit the travel of the
suspension)The front suspension has semi-elliptic multi-leaf
springs mounted to the axle assembly. The rearward
end of the springs are mounted to the frame rail
hangers. The forward end of the springs are attached
to the frame with shackles. The springs and shackles
use rubber bushings to isolate road noise. The shack-
les allow the springs to change their length as the
vehicle moves over various road conditions. The
Fig. 2 Front AxleÐ2WD Vehicles
Fig. 3 YJ Front Suspension
2 - 2 FRONT SUSPENSION AND AXLEJ

spring and axle travel (jounce or rebound) is limited
through use of rubber bumpers mounted on the
frame.
Suspension components which use rubber bushings
should be tightened at vehicle ride height. This will
prevent premature failure of the bushing and main-
tain ride comfort. The bushings should never be lu-
bricated.
The shocks absorbers dampen jounce and rebound
of the vehicle over various road conditions. The top of
the shock absorbers bolt to the frame. The bottom of
the shocks bolt to the axle brackets.
The stabilizer bar is used to minimize vehicle front
sway during turns. The spring steel bar helps control
vehicle body in relationship to the suspension move-
ment. The bar extends across the front underside of
the chassis and connects to the frame rails. Links
connect the bar to the axle brackets. Stabilizer bar
mounts are isolated by rubber bushings.
The track bar is used to minimize front axle side-
to-side movement. The track bar is attached to a
frame rail bracket and axle bracket. The bar uses
bushings at both ends.
FRONT DRIVE AXLE
It is not necessary to remove the complete axle
from the vehicle for routine differential service. If the
differential housing or axle shaft tubes are damaged,
the complete axle assembly can be removed and ser-
viced.
For complete drive axle assembly removal and in-
stallation refer to Drive Axle Assembly Replacement
in this Group.
The removable cover provides for servicing without
removing axle from vehicle.
The integral type housing, hypoid gear design has
the centerline of the pinion set above the centerline
of the ring gear.
The Model 30 axle has the assembly part number
and gear ratio listed on a tag. The tag is attached to
the housing cover (Fig. 4). Build date identification
codes are stamped on the axle shaft tube cover side.
XJ and YJ axles are equipped with an optional
A.B.S. brake system. The A.B.S. tone rings are
pressed onto the axle shaft near the hub and
knuckle. For additional information on the A.B.S.
system refer to Group 5, Brakes.
²XJ vehicles use a non-disconnect axle.
²YJ vehicles use a vacuum disconnect axle (Fig. 5).
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. Thepinion 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:
²Pinion gear rotates the ring gear
²Ring gear (bolted to the differential case) rotates
the case
²Differential pinion gears (mounted on the pinion
mate shaft in the case) rotate the side gears
²Side 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 gears is di-
vided 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. 6).
When turning corners, the outside wheel must
travel a greater distance than the inside wheel. This
difference must be compensated for in order to pre-
vent the wheels from scuffing and skidding through
the turn. To accomplish this, the differential allows
Fig. 4 Model 30 Differential Cover
Fig. 5 Disconnect Feature
JFRONT SUSPENSION AND AXLE 2 - 3

the axle shafts to turn at unequal speeds (Fig. 7). 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 direc-tions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
Fig. 6 Differential OperationÐStraight-Ahead Driving
Fig. 7 Differential OperationÐOn Turns
2 - 4 FRONT SUSPENSION AND AXLEJ

FRONT WHEEL ALIGNMENT
INDEX
page page
Alignment Measurements and Adjustments....... 8
General Information........................ 5Pre-Alignment Inspection.................... 6
GENERAL INFORMATION
Front wheel alignment involves the correct posi-
tioning of the wheels in relation to the vehicle. The
positioning is accomplished through suspension and
steering linkage adjustments. An alignment is con-
sidered essential for efficient steering, good direc-
tional stability and to maximize tire wear. The most
important measurements of front end alignment are
caster, camber and toe position.
Routine inspection of the front suspension
and steering components is a good preventative
maintenance practice. Inspection also helps to
ensure safe operation of the vehicle.
²CASTER is the forward or rearward tilt of the
steering knuckle from vertical. Tilting the top of the
knuckle rearward provides positive caster. Tilting thetop of the knuckle forward provides negative caster.
Caster is a directional stability angle. This angle en-
ables the front wheels to return to a straight ahead
position after turns (Fig. 1).
²CAMBER is the inward or outward tilt of the
wheel relative to the center of the vehicle. Tilting the
top of the wheel inward provides negative camber.
Tilting the top of the wheel outward provides positive
camber. Incorrect camber will cause wear on the in-
side or outside edge of the tire (Fig. 1). The angle is
not adjustable, the damaged component(s) must be
replaced to correct mis-alignment.
²WHEEL TOE POSITION is the difference between
the leading inside edges and trailing inside edges of
the front tires (Fig. 1). Incorrect wheel toe position is
the most common cause of unstable steering and un-
Fig. 1 Wheel Alignment Measurements
JFRONT SUSPENSION AND AXLE 2 - 5

even tire wear. The wheel toe position is thefinal
front wheel alignment adjustment.
²STEERING AXIS INCLINATION ANGLE is mea-
sured in degrees and is the angle that the steering
knuckles are tilted (Fig. 1). The inclination angle has
a fixed relationship with the camber angle. It will not
change except when a spindle or ball stud is dam-
aged or bent. The angle is not adjustable, the dam-
aged component(s) must be replaced to correct mis-
alignment.
WARNING: DO NOT ATTEMPT TO MODIFY ANY
SUSPENSION OR STEERING COMPONENT BY
HEATING AND BENDING.
PRE-ALIGNMENT INSPECTION
Before starting a front wheel alignment, the follow-
ing inspection and necessary corrections must be
completed.(1) Tires with the same recommended air pressure,
size, and thread wear. Refer to Group 22, Tires And
Wheels for diagnosis information.
(2) Front wheel bearings for wear and looseness.
(3) Ball studs, steering linkage pivot points and
steering gear for looseness, roughness, binding or
wear. Refer to Group 19, Steering for additional in-
formation.
(4) Front wheels for excessive radial or lateral
runout and unbalance. Refer to Group 22, Tires And
Wheels for diagnosis information.
(5) Suspension components for wear. Check compo-
nents for correct torque. Refer to Groups 2 and 3,
Suspension and Axle for additional information.
2 - 6 FRONT SUSPENSION AND AXLEJ

SUSPENSION AND STEERING SYSTEM DIAGNOSIS
JFRONT SUSPENSION AND AXLE 2 - 7

ALIGNMENT MEASUREMENTS AND ADJUSTMENTS
Before each alignment reading, the vehicle should
be jounced (rear first, then front). Grasp each
bumper at the center and jounce the vehicle up and
down several times. Always release the bumper in
the down position.Set the front end alignment to
specifications with the vehicle at its NOR-
MALLY RIDE HEIGHT.
CAMBER
The wheel camber angle is preset. This angle is not
adjustable and cannot be altered.
CASTER
Before checking the caster of the front axle for cor-
rect angle, be sure the axle is not bent or twisted.
Road test the vehicle, make left and right turns. If
the steering wheel returns to the center position un-
assisted, the caster angle is correct. If steering wheeldoes not return toward the center position unas-
sisted, an incorrect caster angle is probable.
Caster can be adjusted by installing the appropri-
ate size shims (Fig. 2, 3).Changing caster angle
will also change the front propeller shaft angle.
The propeller shaft angle has priority over
caster. Refer to Group 16, Propeller Shafts for
additional information.
TOE POSITIONÐXJ VEHICLES
The wheel toe position adjustment should be the fi-
nal adjustment.
(1) Start the engine if equipped with power steer-
ing. Turn wheels both ways before straightening the
Fig. 2 AdjustmentÐYJ Vehicles
Fig. 3 AdjustmentÐXJ Vehicles
Fig. 4 Steering LinkageÐXJ (LHD)
2 - 8 FRONT SUSPENSION AND AXLEJ