1994 JEEP CHEROKEE maint

(5) Inspect the reservoir rubber diaphragm seal for
cracks, cuts and distortion.
(6) Inspect the brake fluid tubing fittings and the
master cylinder housing for indications of fluid leak-
age. Repair as necessary.
(7) Install the brake fluid reservoir cover.
ANTI-LOCK BRAKE SYSTEMÐXJ VEHICLES
The anti-lock brake system fluid reservoir for XJ
Vehicles is located in the engine compartment at the
left side of the dash panel.
(1) Turn the ignition switch ON and allow the
pump motor to operate until it automatically de-en-
ergizes.
(2) Clean the cover before removing it.
CAUTION: Over-filling could cause fluid overflow
and possible reservoir damage when the pump mo-
tor energizes.
(3) The brake fluid level should be no lower than
the MIN arrow indicator on the side of the reservoir
(Fig. 8). If not, add brake fluid as necessary. Raise
the fluid level to the MAX arrow indicator only. Do
not over-fill the reservoir.
(4) Turn the ignition switch OFF.
BRAKE SYSTEM INSPECTION
BRAKE FLUID HOSES/TUBING
(1) Inspect all brake fluid rubber hoses (Fig. 9) for
cracks, swelling, kinks, a distorted condition and
fluid leakage.
(2) Inspect the brake fluid hoses and tubing that
are routed along the frame rail.
PADS/LININGS, ADJUSTER, WHEEL CYLINDERS AND
CALIPER
The front disk brake pads can be visually inspected
via the brake caliper inspection ports.(1) Inspect the brake pads and linings for excessive
wear, cracks, charred surfaces and broken rivets.
(2) Inspect the brake pads and linings for contam-
ination with brake fluid, axle lubricant and/or an-
other fluid.
(3) Replace the brake pads and/or linings if they
are worn to within 0.78 mm (1/32 in) of the rivet
head.
(4) Operate the rear brake self-adjuster lever and
pivot. Test the operation of the self-adjuster screw for
ease of movement.
(5) Inspect the self-adjuster components for bent
areas, frayed cables, loose or overheated springs, and
a binding condition.
Fig. 7 Reservoir Fluid LevelÐTypicalFig. 8 Reservoir Fluid LevelÐAnti-Lock Brake
System
Fig. 9 Rubber Brake Fluid HoseÐTypical
JLUBRICATION AND MAINTENANCE 0 - 33

(6) Inspect the disc brake caliper dust boot for cor-
rect installation, damage/tears and indications of
brake fluid leakage. Inspect the bushings and pins
for corrosion, tears and a binding condition.
(7) Pull the rear wheel cylinder dust boot back to
expose the wheel cylinder housing and inspect for
fluid leaks. Inspect the pistons and cylinder bores for
proper appearance.
(8) Inspect the brake differential warning valve
and housing for indications of leakage, kinked hoses
and loose fittings.
PARK BRAKE
(1) As applicable, engage the park brake lever or
pedal and then release it.
(2) If the park brake is functioning normally, test
it for smooth operation and vehicle-holding capabil-
ity.
(3) Inspect the park brake cables for kinks, fraying
and a binding condition.
(4) With the park brake released, the rear wheels
should rotate without restriction. Adjust the park
brake cable tension at the equalizer (Fig. 10), if nec-
essary.
(5) Repair any park brake malfunctions.
BRAKE OPERATIONAL TEST
(1) Drive the vehicle and test for proper brake ac-
tion.
(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 5ÐBrakes 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 pe-
riodically to ensure even tread wear and maximum
tread life. The tires/wheels should be rotated initially
after the first 12 000-km (7,500-miles). Thereafter,
after each 24 000-km (15,000-miles) interval of vehi-
cle operation has elapsed.
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
22ÐTires And Wheels.
ROTATION
Refer to Group 22ÐTires And Wheels for the rec-
ommended method of tire/wheel rotation for a Jeept
vehicle.
BODY COMPONENTS
RECOMMENDED MAINTENANCE
Body components should be lubricated (as required)
after each 48 000-km (30,000-miles) interval of vehi-
cle operation has elapsed.
LUBRICANT SPECIFICATIONS
All applicable exterior and interior body compo-
nents should be:
²inspected for excessive wear,
²cleaned, and
²all pivot/sliding contact areas of the components
should be lubricated with the specified lubricant.
Refer to the Body Lubricant Specifications chart
below. When excessive wear is apparent, replace/re-
pair as necessary.
LUBRICATION
All pivoting and sliding contact areas, including:
²seat tracks,
²door hinges/latches/strikers, and
²liftgate/tailgate/hood hinges (Fig. 11),
should be lubricated periodically to ensure quiet,
easy operation and to protect against wear and cor-
rosion.
(1) As required, lubricate the body components
with the specified lubricants.
(2) When lubricating door weatherstrip seals, ap-
ply the lubricant to a cloth and wipe it on the seal.
(3) Prior to the application of lubricant, the compo-
nent should be wiped clean to remove dust, grit and
debris. After lubrication, any excess lubricant should
be removed.
Fig. 10 Park Brake Equalizer (XJ)ÐTypical
0 - 34 LUBRICATION AND MAINTENANCEJ

(4) Extra close attention should be given to exter-
nal key lock cylinders during the autumn and winter
months to ensure protection from water and ice.(5) Extra close attention should also be given to
the hood latch components to ensure proper function-
ing.
HEADLAMPS
RECOMMENDED MAINTENANCE
Approximately every six months the headlamps
should be displayed on a vertical test surface. This
will ensure that the headlamps are positioned for
safe night-time driving.
BEAM AIM ADJUSTMENT
(1) Changes in the vehicle front and rear suspen-
sion will alter the headlamp beam patterns and this
can cause unsafe night-time driving conditions.
(2) If a vehicle is loaded the headlamp beam pat-
terns should be displayed on an vertical test surface
and the headlamps re-aimed.
(3) Observe the headlamp beam patterns on an ap-
propriate vertical test surface and, if necessary, ad-
just the headlamp beam aim.
(4) If necessary, refer to Group 8LÐLamps for
headlamp aim adjustment procedures.
BODY LUBRICANT SPECIFICATIONS
Fig. 11 Hood Hinge LubricationÐXJ Vehicles
JLUBRICATION AND MAINTENANCE 0 - 35

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

FRONT WHEEL ALIGNMENT
INDEX
page page
Alignment Measurements and Adjustments...... 6
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 the
top of the knuckle forward provides negative caster.
Caster is a directional stability angle whichenables 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).
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-
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
Fig. 1 Wheel Alignment Measurements
JFRONT SUSPENSION AND AXLE 2 - 5

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

BACKLASH AND CONTACT PATTERN ANALYSIS
(1) Rotate assembly several revolutions to seat
bearings. Measure backlash at three equally spaced
locations around the perimeter of the ring gear with
a dial indicator (Fig. 63).
The ring gear backlash must be within 0.005 -
0.008 inch (0.12 - 0.20 mm). It cannot vary more
than 0.002 inch (0.05 mm) between the points
checked.
If backlash must be adjusted, transfer shims from
one side of carrier to the other side. Adjust the back-
lash accordingly (Fig. 64).DO NOT INCREASE
THE TOTAL SHIM PACK THICKNESS, EXCES-
SIVE BEARING PRELOAD AND DAMAGE
WILL OCCUR.If the mesh and backlash steps have been followed
in the procedures above, good gear teeth contact pat-
terns should exist.
The ring gear teeth contact patterns will show if
the pinion gear depth is correct. It will also show if
the ring gear backlash has been adjusted correctly.
The backlash must be maintained within the speci-
fied limits until the correct tooth contact patterns are
obtained.
(2) Apply a thin coat of hydrated ferric oxide (yel-
low oxide of iron) to the drive and coast side of the
ring gear teeth.
(3) Rotate the ring gear one complete revolution in
both directions while a load is being applied. Insert a
pry bar between the differential housing and the case
flange. This action will produce distinct contact pat-
terns on both the drive side and coast side of the ring
gear teeth.
(4) Note patterns in compound. Refer to (Fig. 65)
for interpretation of contact patterns and adjust ac-
cordingly.
FINAL ASSEMBLY
(1) Install the axle shafts. Refer to Axle Shaft In-
stallation in this Group.
(2) Scrape the residual sealant from the housing
and cover mating surfaces. Clean the mating sur-
faces with mineral spirits. Apply a bead of MOPARt
Silicone Rubber Sealant on the housing cover (Fig.
66). Allow the sealant to cure for a few minutes.
Install the housing cover within 5 minutes af-
ter applying the sealant. If not installed the seal-
ant must be removed and another bead applied.
(3) Install the cover on the differential with the at-
taching bolts. Install the identification tag. Tighten
the cover bolts with 41 Nzm (30 ft. lbs.) torque.
CAUTION: Overfilling the differential can result in
the lubricant foaming and overheating.
(4) Refill the differential housing with the speci-
fied quantity of MOPARtHypoid Gear Lubricant.
(5) Install the fill hole plug and tighten to 34 Nzm
(25 ft. lbs.) torque.Fig. 63 Ring Gear Backlash Measurement
Fig. 64 Backlash Shim Adjustment
2 - 44 FRONT SUSPENSION AND AXLEJ