1994 JEEP CHEROKEE oil

FRONT SUSPENSION AND AXLE
CONTENTS
page page
AXLE NOISE/VIBRATION DIAGNOSIS....... 16
FRONT WHEEL ALIGNMENT............... 5
GENERAL INFORMATION.................. 1
MODEL 30 AXLE AND TUBE AXLE (2WD) . . 20TORQUE SPECIFICATIONS................ 47
XJ FRONT SUSPENSION................. 10
YJ FRONT SUSPENSION................. 13
GENERAL INFORMATION
FRONT SUSPENSION
XJ VEHICLES
The Cherokee front suspension is a link/coil design
comprised of (Fig. 1);
²Drive axle (4WD), tube axle (2WD)
²Track bar
²Stabilizer bar
²Upper and lower suspension arms
²Coil springs
²Dual-action shock absorbers²Jounce bumpers (used to limit the travel of the
suspension)
The link/coil suspension allows each wheel to adapt
to different road surfaces without greatly affecting
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
Fig. 1 XJ Front Suspension
JFRONT SUSPENSION AND AXLE 2 - 1

axle assembly to the frame. The lower arms uses
shims at the frame mount to allow for adjustment of
caster and pinion angle. The suspension arm travel
(jounce or rebound) is limited through the use of rub-
ber bumpers.
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 frame. The bot-
tom of the shocks are bolted to the axle spring
bracket.
The stabilizer bar is used to minimize vehicle front
sway 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 frame 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 does the four-wheel
drive front axle. The steering knuckles and hub bear-
ing 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 uses semi-elliptic multi-leaf
springs mounted on the drive axle. The rearward end
of the springs are mounted to the frame rail hangers
through rubber bushings. The bushings isolate road
noise as the springs move. The forward end of the
springs are attached to the frame with shackles. The
spring and shackles use rubber bushings to isolate
road noise. The shackles allow the springs to changetheir length as the vehicle moves over various road
conditions. The spring and axle travel (jounce or re-
bound) 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.
Fig. 2 Front AxleÐ 2WD Vehicles
Fig. 3 YJ Front Suspension
2 - 2 FRONT SUSPENSION AND AXLEJ

XJ FRONT SUSPENSION
INDEX
page page
Axle Bushing Replacement................. 11
Coil Spring............................. 13
Lower Suspension Arm.................... 11
Service Information....................... 10
Shock Absorber.......................... 12Spring and Shock Diagnosis................ 12
Stabilizer Bar............................ 10
Track Bar.............................. 10
Upper Suspension Arm.................... 11
SERVICE INFORMATION
CAUTION: Suspension components that use rubber
bushings should be tightened with the vehicle at
the normal height. It is important to have the
springs supporting the weight of the vehicle when
the fasteners are torqued. If the springs are not at
their normal ride position, vehicle ride comfort
could be affected along with premature bushing
wear. Rubber bushings must never be lubricated.
TRACK BAR
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the cotter pin and nut from the ball
stud end at the frame rail bracket (Fig. 1).
A puller tool may be necessary to separate the
ball stud from the frame rail bracket.
(3) Remove the bolt and flag nut from the axle
shaft tube bracket (Fig. 1). Remove the track bar.
INSTALLATION
(1) Install the track bar at axle tube bracket. Loosely
install the retaining bolt and flag nut (Fig. 1).
(2) It may be necessary to pry the axle assembly
over to install the track bar at the frame rail. Install
track bar at the frame rail bracket. Install the re-
taining nut on the stud (Fig. 1).
(3) Remove the supports and lower the vehicle.
(4) Tighten the retaining bolt at the axle shaft
tube bracket to 100 Nzm (74 ft. lbs.) torque.
(5) Tighten the ball stud nut to 81 Nzm (60 ft. lbs.)
torque. Install a new cotter pin.
STABILIZER BAR
REMOVAL
(1) Raise and support the vehicle.
(2) Disconnect the stabilizer bar links from the
axle brackets (Fig. 2).
(3) Disconnect the stabilizer bar from the links.
(4) Disconnect the stabilizer bar clamps from the
frame rails. Remove the stabilizer bar.
Fig. 2 Stabilizer BarFig. 1 Track Bar
2 - 10 FRONT SUSPENSION AND AXLEJ

(2) Install the bolts and finger tighten the nuts
(Fig. 3).
(3) Remove support and lower the vehicle.
(4) Tighten the front and rear nuts to 115 Nzm (85
ft. lbs.) torque.
SPRING AND SHOCK DIAGNOSIS
A squeak noise from the shock absorber can be pro-
duced if movement between the rubber bushings and
the metal occurs. This noise can usually be stopped
by tightening the attaching nuts. If the squeak noisepersists, inspect for damaged and worn bushings, and
attaching components. Repair as necessary.
The shock absorber bushings do not require any
type of lubrication. Do not lubricate the bushings to
reduce bushing noise. Grease or mineral oil-base lu-
bricants will deteriorate the bushing rubber.
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.
SHOCK ABSORBER
REMOVAL
(1) Remove the nut, retainer and grommet from
the upper stud in the engine compartment (Fig. 6).
(2) Remove the lower nuts and bolts from the axle
bracket (Fig. 6). Remove the shock absorber.
INSTALLATION
(1) Position the lower retainer and grommet on the
upper stud. Insert the shock absorber through the
shock tower hole.
(2) Install the lower bolts and nuts. Tighten nuts
to 19 Nzm (14 ft. lbs.) torque.
(3) Install the upper grommet and retainer on the
stud in the engine compartment. Install the nut and
tighten to 10 Nzm (8 ft. lbs.) torque.
Fig. 6 Coil Spring & Shock Absorber
Fig. 5 Axle Bracket Bushing Installation
2 - 12 FRONT SUSPENSION AND AXLEJ

COIL SPRING
REMOVAL
(1) Raise and support the vehicle. Position a hy-
draulic jack under the axle to support it.
(2) Remove the wheel if necessary.
(3) Mark and disconnect the front propeller shaft
from the axle.
(4) Disconnect the lower suspension arms from the
axle (Fig. 6).
(5) Disconnect the stabilizer bar link and shock ab-
sorber from the axle.
(6) Disconnect the track bar from the frame rail
bracket.
(7) Disconnect the drag link from the pitman arm.
(8) Lower the axle until the spring is free from the
upper mount. Remove the coil spring clip (Fig. 6) and
remove the spring.
(9) Remove the jounce bumper if necessary from
the upper spring mount (Fig. 6).
INSTALLATION
(1) Install the jounce bumper on the upper spring
mount. Tighten the bolt to 42 Nzm (31 ft. lbs.) torque
(Fig. 6).
(2) Position the coil spring on the axle pad. Install
the spring clip and bolt (Fig. 6). Tighten bolt to 21
Nzm (16 ft. lbs.) torque.
(3) Raise the axle into position until the spring
seats in the upper mount.
(4) Connect the stabilizer bar links and shock ab-
sorbers to the axle bracket. Connect the track bar to
the frame rail bracket.
(5) Install the lower suspension arms to the axle.
DO NOT TIGHTEN AT THIS TIME.
(6) Install the front propeller shaft to the axle.
(7) Remove the supports and lower the vehicle.
(8) Tighten lower suspension arms nuts to 115
Nzm (85 ft. lbs.) torque.
YJ FRONT SUSPENSION
INDEX
page page
Leaf Spring............................. 14
Leaf Spring Eye Bushing Replacement........ 15
Service Information....................... 13
Shock Absorber.......................... 14Spring and Shock Diagnosis................ 14
Stabilizer Bar............................ 14
Track Bar.............................. 13
SERVICE INFORMATION
It is important to have the springs supporting
the weight of the vehicle when the track bar fas-
teners are being torqued. If the springs are not
at their normal ride position, vehicle ride com-
fort could be affected along with premature rub-
ber bushing wear.
TRACK BAR
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the retaining nuts and bolts (Fig. 1)
from the axle bracket and frame bracket. Remove
track bar.
INSTALLATION
(1) Position track bar at axle shaft tube bracket.
Loosely install the retaining bolt and nut (Fig. 1).
(2) Loosely install the retaining bolt and nut at
the frame bracket.
(3) Remove support and lower vehicle.
(4) Tighten the retaining nut at the axle shaft
tube bracket to 100 Nzm (74 ft. lbs.) torque.
(5) Tighten the retaining nut at the frame bracket
to 142 Nzm (105 ft. lbs.) torque.
Fig. 1 Track Bar
JFRONT SUSPENSION AND AXLE 2 - 13

STABILIZER BAR
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the retaining nut from the connecting
link bolt (Fig. 2).
(3) Remove the retaining clamps from frame rails
(4) Remove the stabilizer bar.
INSTALLATION
(1) Inspect the stabilizer bar bushings (Fig. 2). Re-
place the bushings if cracked, cut, distorted, or worn.
(2) Position the stabilizer bar on the frame. Install
the retaining brackets and fasteners. Tighten bolts to
41 Nzm (30 ft. lbs.) torque.
(3) Install the link upper bolts and nuts. Tighten
the nuts to 61 Nzm (45 ft. lbs.) torque.
(4) Tighten the link spring bracket nuts to 61 Nzm
(45 ft. lbs.) torque.
(5) Lower the vehicle.
SPRING AND SHOCK DIAGNOSIS
A squeak noise from the shock absorber or springs
can be produced if movement between the rubber
bushings and the metal occurs. This noise can usu-
ally be stopped by tightening the attaching nuts. If
the squeak noise persists, inspect for damaged and
worn bushings, and attaching components. Repair as
necessary if any of these conditions exist.
The shock absorber bushings do not require any
type of lubrication. Do not lubricate the bushings to
reduce bushing noise. Grease or mineral oil-base lu-
bricants will deteriorate the bushing rubber.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.
SHOCK ABSORBER
REMOVAL
(1) Remove the nut, retainer and grommet from
the upper stud on the frame bracket (Fig. 3).
(2) Raise and support the vehicle.
(3) Remove the nut, washers and bolt from the
shock absorber lower eye (Fig.3).
(4) Remove the shock absorber.
(5) Remove the remaining grommet and retainer
from the shock absorber stud.
INSTALLATION
(1) Position the lower retainer and grommet on the
upper stud. Insert the shock absorber through the
shock tower hole.
(2) Install the lower bolts and nuts. Tighten the
nuts to 61 Nzm (45 ft. lbs.) torque.
(3) Install the upper grommet and retainer on the
stud on the frame bracket. Install the nut and
tighten to 12 Nzm (9 ft. lbs.) torque.
LEAF SPRING
REMOVAL
(1) Raise the vehicle.
Fig. 2 Stabilizer Bar
Fig. 3 Spring & Shock Absorber
2 - 14 FRONT SUSPENSION AND AXLEJ

MODEL 30 AXLE AND TUBE AXLE (2WD)
INDEX
page page
Axle Bushing Replacement................. 32
Axle Shaft Ð Cardan U-Joint................ 25
Axle Specifications....................... 46
Backlash and Contact Pattern Analysis........ 44
Cleaning/Inspection....................... 35
Differential and Pinion Measurement.......... 38
Differential Assembly...................... 36
Differential Disassembly.................... 34
Differential Installation..................... 43
Differential Removal...................... 32
Differential Shim Pack Measurement and Adjustment.42
Drive Axle Assembly ReplacementÐXJ Vehicles . 21
Drive Axle Assembly ReplacementÐYJ Vehicles . 21Final Assembly.......................... 44
Hub Bearing and Axle Shaft................ 24
Information............................. 20
Inner Axle Shaft Oil Seal Replacement........ 33
Lubricant Change........................ 22
Lubricant Specifications.................... 20
Pinion Gear Assembly/Installation............ 40
Pinion Gear Depth Information.............. 37
Pinion Removal/Disassembly................ 34
Pinion Seal Replacement.................. 23
Steering Knuckle and Ball Studs............. 30
Vacuum Disconnect Axle Ð YJ Vehicles....... 26
INFORMATION
The housing for Model 30 front axles consists of an
iron center casting (differential housing) with axle
shaft tubes extending from either side. The tubes are
pressed into and welded to the differential housing to
form a one-piece axle housing.
The integral type housing, hypoid gear design has
the centerline of the pinion set above the centerline
of the ring gear.
The axle has a fitting for a vent hose used to re-
lieve internal pressure caused by lubricant vaporiza-
tion and internal expansion.
The axles are equipped with semi-floating axle
shafts, meaning that loads are supported by the hub
bearings. The axle shafts are retained by nuts at the
hub bearings. The hub bearings are bolted to the
steering knuckle at the outboard end of the axle tube
yoke. The hub bearings are serviced as an assembly.
The axles are equipped with ABS brake sensors.
The sensors are attached to the knuckle assemblies
and tone rings are pressed on the axle shaft.Use
care when removing axle shafts as NOT to dam-
age the tone wheel or the sensor.
The stamped steel cover provides a means for in-
spection and servicing the differential.
The Model 30 axle has the assembly part number
and gear ratio listed on a tag. The tag is attached to
the housing cover. Build date identification codes are
stamped on the axle shaft tube cover side.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a roll
pin. Differential bearing preload and ring gear back-
lash is adjusted by the use of shims (select thick-
ness). The shims are located between the differential
bearing cones and case. Pinion bearing preload is set
and maintained by the use of collapsible spacer.
PINION GEAR DEPTH MEASUREMENT WITH
PINION GAUGE SET 6774, Pinion Block 6733 and
Dial Indicator C-3339 is performed when;²Axle/differential housing is being replaced
²Original pinion depth shim pack is lost or mis-
placed
²Replacing the differential case
²Original differential bearing shim pack is lost or
misplaced
COMMAND-TRACÐYJ VEHICLES
The Command-Trac system is a vacuum disconnect
axle. The system has a two-piece axle shaft coupled
together by a shift collar. For two-wheel drive oper-
ation, the vacuum motor and shift fork disengages
the axle shaft splines. For four-wheel drive opera-
tion, the vacuum motor and shift fork engages the
splines.
SELEC-TRACÐXJ VEHICLES
The Selec-Trac system is a non-disconnect axle.
Shifting from two-wheel to four-wheel drive is at the
transfer case.
For XJ vehicles equipped withSelec-Tracand
ABS brake system, refer to Group 5ÐBrakes for ad-
ditional service information.
LUBRICANT SPECIFICATIONS
Multi-purpose, hypoid gear lubricant should be
used for Model 30 axles. The lubricant should have
MIL-L-2105C and API GL 5 quality specifications.
MOPARtHypoid Gear Lubricant conforms to both of
these specifications.
²The factory fill for the Model 30 axle is SAE 75W
gear lubricant.Do not use heavier weight lubri-
cant, this will cause axle engagement difficulties.
²The factory installed lubricant quantity for the
NON-DISCONNECT TYPE AXLE is 5061 fluid oz..
²The factory installed lubricant quantity for the
VACUUM-DISCONNECT TYPE AXLE is 5661 fluid
oz..
2 - 20 FRONT SUSPENSION AND AXLEJ

Refer to Group 0, Lubrication and Maintenance for
additional information regarding temperature range,
viscosity and fluid level.
CAUTION: If the axle is submerged in water, the lu-
bricant must be replaced immediately to avoid the
possibility of premature axle failure.
DRIVE AXLE ASSEMBLY REPLACEMENTÐXJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly in behind the lower
suspension arm frame brackets.
(2) Remove the front wheels.
(3) Remove the brake components and ABS brake
sensor (if equipped). Refer to Group 5ÐBrakes.
(4) On 4WD vehicles, disconnect the axle vent
hose.
(5) On 4WD vehicles, mark the drive shaft yoke
and axle pinion yoke for alignment reference. Discon-
nect the drive shaft from the axle.
(6) Disconnect the stabilizer bar link at the axle
bracket.
(7) Disconnect the shock absorbers from axle
bracket.
(8) Disconnect the track bar from the axle bracket.
(9) Disconnect the tie rod and drag link from the
steering knuckle. Disconnect the steering dampener
from the axle bracket.
(10) Support the axle with a hydraulic jack under
the differential.
(11) Disconnect the upper and lower suspension
arms from the axle bracket.
(12) Lower the jack enough to remove the axle.
The coil springs will drop with the axle.
(13) Remove the coil springs from the axle bracket.
INSTALLATION
CAUTION: All suspension components that use rub-
ber bushings should be tightened with the vehicle
at the ride height. It is important to have the
springs supporting the weight of the vehicle when
the fasteners are torqued. If the springs are not at
their normal ride position, vehicle ride comfort
could be affected along with premature rubber
bushing wear. Rubber bushings must never be lu-
bricated.
(1) Install the springs and retainer clip. Tighten
the retainer bolts to 21 Nzm (16 ft. lbs.) torque.
(2) Support the axle on a hydraulic jack under the
differential. Position the axle under the vehicle.
(3) Raise the axle with a floor jack and align it
with the spring pads.(4) Position the upper and lower suspension arm at
the axle bracket. Install bolts and nuts finger
tighten.
(5) Connect the track bar to the axle bracket and
install the bolt.Do not tighten at this time.
It is important that the springs support the
weight of the vehicle when the track bar is con-
nected. If the springs are not at their usual po-
sition, the vehicle ride comfort could be affected.
(6) Install the shock absorber and tighten the bolt
to 19 Nzm (14 ft. lbs.) torque.
(7) Install the stabilizer bar link to the axle
bracket. Tighten the nut to 95 Nzm (70 ft. lbs.)
torque.
(8) Install the drag link and tie rod to the steering
knuckles and tighten the nuts to 47 Nzm (35 ft. lbs.)
torque. Install the steering dampener to the axle
bracket and tighten the nut to 75 Nzm (55 ft. lbs.)
torque.
(9) Install the brake components and ABS brake
sensor (if equipped). Refer to Group 5ÐBrakes.
(10) On 4WD vehicles, connect the vent hose to the
tube fitting.
(11) On 4WD vehicles, align the reference marks
and connect the drive shaft to the axle yoke. Tighten
the U-joint clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(12) Check differential lubricant and add if neces-
sary.
(13) Install the wheel and tire assemblies.
(14) Remove the supports and lower the vehicle.
(15) Tighten the upper suspension arm nuts to 75
Nzm (55 ft. lbs.) torque. Tighten the lower suspension
arm nuts to 115 Nzm (85 ft. lbs.) torque.
(16) Tighten the track bar bolt at the axle bracket
to 100 Nzm (74 ft. lbs.) torque.
(17) Check the front wheel alignment.
DRIVE AXLE ASSEMBLY REPLACEMENTÐYJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly behind the spring
frame brackets.
(2) Remove the front wheels.
(3) Remove the brake components and ABS brake
sensor (if equipped). Refer to Group 5ÐBrakes.
(4) Disconnect the axle vent hose and axle shift
motor vacuum harness.
(5) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(6) Disconnect the stabilizer bar link at the axle
bracket.
(7) Disconnect the shock absorbers from axle
bracket.
(8) Disconnect the track bar from the axle bracket.
JFRONT SUSPENSION AND AXLE 2 - 21