INSTALLATION
(1) Wipe the axle tube bore clean. Remove any old
sealer or burrs from the tube.
(2) Install anewaxle seal with Installer C-4076-B
and Handle C-4735-1. When the tool contacts the
axle tube, the seal is installed to the correct depth.
(3) Coat the lip of the seal with axle lubricant for
protection prior to installing the axle shaft.
(4) Install the axle shaft.
(5) Check and fill gear lubricant.
(6) Install wheel and tire assembly.
(7) Remove support and lower vehicle.
AXLE BEARINGS
REMOVAL
(1) Raise and support vehicle.
(2) Remove axle shaft.
(3) Remove axle shaft seal from the axle tube with
a small pry bar (Fig. 22).
NOTE: The seal and bearing can be removed at the
same time with the bearing removal tool.
(4) Remove axle shaft bearing with Bearing
Removal Tool Set 6310 and Adapter Foot 6310-9 (Fig.
23).
INSTALLATION
(1) Wipe the axle tube bore clean. Remove any old
sealer or burrs from the tube.
(2) Install axle shaft bearing with Installer C-4198
and Handle C-4171.NOTE: Install bearing with part number against the
installer.
(3) Install anewaxle seal with Installer C-4198
and Handle C-4171. When the tool contacts the axle
tube, the seal is installed to the correct depth.
(4) Coat the lip of the seal with axle lubricant for
protection prior to installing the axle shaft.
(5) Install the axle shaft.
(6) Check and fill gear lubricant.
(7) Install wheel and tire assembly.
(8) Remove support and lower vehicle.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Mark the universal joint, pinion yoke and pin-
ion shaft for installation reference.
(3) Remove propeller shaft from pinion yoke.
(4) Remove the wheel and tire assemblies.
(5) Remove the brake drums.
(6) Rotate the pinion yoke three or four times.
Fig. 22 Axle Seal
1 - AXLE TUBE
2 - AXLE SEAL
3-PRYBAR
Fig. 23 Axle Shaft Bearing
1 - NUT
2 - GUIDE PLATE
3 - GUIDE
4 - THREADED ROD
5 - ADAPTER
6 - FOOT
7 - AXLE TUBE
3 - 102 REAR AXLE-81/4KJ
AXLE SHAFT SEALS (Continued)
lbs.) increments until proper rotating torque is
achieved.
NOTE: The bearing rotating torque should be con-
stant during a complete revolution of the pinion. If
the rotating torque varies, it indicates a binding
condition.
(9) The seal replacement is unacceptable if the
final pinion nut torque is less than 285 N´m (210 ft.
lbs.).
(10) Install the propeller shaft with the installa-
tion reference marks aligned.
(11) Install the brake drums.
(12) Check the differential housing lubricant level.
(13) Install wheel and tire assemblies and lower
the vehicle.
DIFFERENTIAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove fill hole plug from the differential
housing cover.
(3) Remove differential housing cover and drain
housing.
(4) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.Do not use water,
steam, kerosene or gasoline for cleaning.(5) Remove the axle shafts.
NOTE: Side play resulting from bearing races being
loose on case hubs requires replacement of the dif-
ferential case.
(6) Mark the differential housing and bearing caps
for installation reference (Fig. 28).
(7) Remove bearing threaded adjuster locks from
each bearing cap.
(8) Loosen bearing cap bolts, them loosen the
threaded adjusters with Wrench C-4164 (Fig. 29).
Fig. 27 Pinion Rotation Torque
1 - PINION YOKE
2 - INCH POUND TORQUE WRENCH
Fig. 28 Reference Mark
1 - REFERENCE MARKS
2 - REFERENCE MARKS
3 - DIFFERENTIAL HOUSING
4 - BEARING CAP
Fig. 29 Threaded Adjuster
1 - AXLE TUBE
2 - BACKING PLATE
3 - THREAD ADJUSTER WRENCH
3 - 104 REAR AXLE-81/4KJ
PINION SEAL (Continued)
(6) Install adjuster locks on the bearing caps.
(7) Install axle shafts.
(8) Apply a bead of red Mopar silicone rubber axle
sealant or equivalent to the housing cover (Fig. 33).
CAUTION: If cover is not installed within 3 to 5 min-
utes, the cover must be cleaned and new RTV
applied or adhesion quality will be compromised.
(9) Install cover and tighten bolts in a criss-cross
pattern to 41 N´m (30 ft. lbs.).
(10) Fill differential with gear lubricant to bottom
of the fill plug hole.
(11) Install the fill hole plug.
(12) Install wheel and tire assemblies.
(13) Remove support and lower vehicle.
(14) Trac-loktdifferential equipped vehicles should
be road tested by making 10 to 12 slow figure-eight
turns. This maneuver will pump the lubricant
through the clutch discs to eliminate a possible chat-
ter noise complaint.DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT
The most common problem is a chatter noise when
turning corners. Before removing the unit for repair,
drain, flush and refill the axle with the specified
lubricant. A container of Mopar Trac-loktLubricant
(friction modifier) should be added after repair ser-
vice or during a lubricant change.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque (Fig. 34).
(6) If rotating torque is less than 41 N´m (56 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
Fig. 33 Differential Cover Sealant
1 - SEALANT
2 - DIFFERNTIAL COVER
Fig. 34 ROTATING TORQUE TEST
1 - SPECIAL TOOL WITH BOLT IN CENTER HOLE
2 - TORQUE WRENCH
3 - 106 REAR AXLE-81/4KJ
DIFFERENTIAL (Continued)
SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn, damaged
tires.
NOTE: Some pedal pulsation may be felt during
ABS activation.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables.
²Loose/worn wheel bearing.
²Seized caliper or wheel cylinder piston.
²Caliper binding on corroded bushings or rusted
slide surfaces.
²Loose caliper mounting.
²Drum brake shoes binding on worn/damaged
support plates.
²Mis-assembled components.²Long booster output rod.
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Rusty caliper slide surfaces
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.
5 - 4 BRAKES - BASEKJ
BRAKES - BASE (Continued)
BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
mile or two. However, if the lining is both soaked and
dirt contaminated, cleaning and/or replacement will
be necessary.
BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of
leaking calipers or wheel cylinders, worn seals, driv-
ing through deep water puddles, or lining that has
become covered with grease and grit during repair.
Contaminated lining should be replaced to avoid fur-
ther brake problems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components
may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and
pull. A worn or damaged tire can also cause pull.
Severely worn tires with very little tread left can
produce a grab-like condition as the tire loses and
recovers traction. Flat-spotted tires can cause vibra-
tion and generate shudder during brake operation. A
tire with internal damage such as a severe bruise,
cut, or ply separation can cause pull and vibration.
BRAKE NOISES
Some brake noise is common with rear drum
brakes and on some disc brakes during the first few
stops after a vehicle has been parked overnight or
stored. This is primarily due to the formation of trace
corrosion (light rust) on metal surfaces. This light
corrosion is typically cleared from the metal surfaces
after a few brake applications causing the noise to
subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that
are wet or contaminated with brake fluid, grease, or
oil. Glazed linings and rotors with hard spots can
also contribute to squeak. Dirt and foreign material
embedded in the brake lining will also cause squeak/
squeal.
A very loud squeak or squeal is frequently a sign of
severely worn brake lining. If the lining has worn
through to the brake shoes in spots, metal-to-metal
contact occurs. If the condition is allowed to continue,
rotors and drums can become so scored that replace-
ment is necessary.
BRAKE CHATTER
Brake chatter is usually caused by loose or worn
components, or glazed/burnt lining. Rotors with hard
spots can also contribute to chatter. Additional causesof chatter are out-of-tolerance rotors, brake lining not
securely attached to the shoes, loose wheel bearings
and contaminated brake lining.
THUMP/CLUNK NOISE
Thumping or clunk noises during braking are fre-
quentlynotcaused by brake components. In many
cases, such noises are caused by loose or damaged
steering, suspension, or engine components. However,
calipers that bind on the slide surfaces can generate
a thump or clunk noise. In addition, worn out,
improperly adjusted, or improperly assembled rear
brake shoes can also produce a thump noise.
STANDARD PROCEDURE
STANDARD PROCEDURE - PRESSURE
BLEEDING
Use Mopar brake fluid, or an equivalent quality
fluid meeting SAE J1703-F and DOT 3 standards
only. Use fresh, clean fluid from a sealed container at
all times.
Do not pump the brake pedal at any time while
bleeding. Air in the system will be compressed into
small bubbles that are distributed throughout the
hydraulic system. This will make additional bleeding
operations necessary.
Do not allow the master cylinder to run out of fluid
during bleed operations. An empty cylinder will allow
additional air to be drawn into the system. Check the
cylinder fluid level frequently and add fluid as
needed.
Bleed only one brake component at a time in the
following sequence:
²Master Cylinder
²Combination Valve
²Right Rear Wheel
²Left Rear Wheel
²Right Front Wheel
²Left Front Wheel
Follow the manufacturers instructions carefully
when using pressure equipment. Do not exceed the
tank manufacturers pressure recommendations. Gen-
erally, a tank pressure of 15-20 psi is sufficient for
bleeding.
Fill the bleeder tank with recommended fluid and
purge air from the tank lines before bleeding.
Do not pressure bleed without a proper master cyl-
inder adapter. The wrong adapter can lead to leak-
age, or drawing air back into the system. Use
adapter provided with the equipment or Adapter
6921.
KJBRAKES - BASE 5 - 5
BRAKES - BASE (Continued)
STANDARD PROCEDURE - DISC BRAKE
ROTOR
The disc brake rotor can be machined if scored or
worn. The lathe must machine both sides of the rotor
simultaneously with dual cutter heads. The rotor
mounting surface must be clean before placing on the
lathe. Equipment capable of machining only one side
at a time may produce a tapered rotor. A hub
mounted on-vehicle lathe is recommended. This type
of lathe trues the rotor to the vehicles hub/bearing.CAUTION: Brake rotors that do not meet minimum
thickness specifications before or after machining
must be replaced.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the caliper adapter (Fig. 30). (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - REMOVAL).
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose will result. Provide a suitable support to hang
the caliper securely.
(4) Remove the disc brake rotor.
INSTALLATION
(1) Install the disc brake rotor to the hub.
(2) Install the caliper mounting adapter. (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(3) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
Fig. 28 Checking Rotor Runout And Thickness
Variation
1 - DIAL INDICATOR
Fig. 29 Measuring Rotor Thickness
1 - MICROMETER
2 - ROTOR
Fig. 30 DISC BRAKE ROTOR
1 - DISC BRAKE ROTOR
2 - CALIPER ADAPTER
3 - DISC BRAKE CALIPER
4 - SHOES
KJBRAKES - BASE 5 - 19
ROTORS (Continued)
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications and SAE J1703 standards.
No other type of brake fluid is recommended or
approved for usage in the vehicle brake system. Use
only Mopar brake fluid or an equivalent from a
tightly sealed container.
CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. An
open container will absorb moisture from the air
and contaminate the fluid.
CAUTION: Never use any type of a petroleum-based
fluid in the brake hydraulic system. Use of such
type fluids will result in seal damage of the vehicle
brake hydraulic system causing a failure of the
vehicle brake system. Petroleum based fluids would
be items such as engine oil, transmission fluid,
power steering fluid, etc.
DRUM
DIAGNOSIS AND TESTING - BRAKE DRUM
The maximum allowable diameter of the drum
braking surface is indicated on the drum outer edge.
Generally, a drum can be machined to a maximum of
1.52 mm (0.060 in.) oversize. Always replace the
drum if machining would cause drum diameter to
exceed the size limit indicated on the drum.
BRAKE DRUM RUNOUT
Measure drum diameter and runout with an accu-
rate gauge. The most accurate method of measure-
ment involves mounting the drum in a brake lathe
and checking variation and runout with a dial indi-
cator.
Variations in drum diameter should not exceed
0.076 mm (0.003 in.). Drum runout should not exceed
0.20 mm (0.008 in.) out of round. Machine the drum
if runout or variation exceed these values. Replace
the drum if machining causes the drum to exceed the
maximum allowable diameter.
STANDARD PROCEDURES - BRAKE DRUM
MACHINING
The brake drums can be machined on a drum lathe
when necessary. Initial machining cuts should be lim-
ited to 0.12 - 0.20 mm (0.005 - 0.008 in.) at a time as
heavier feed rates can produce taper and surface
variation. Final finish cuts of 0.025 to 0.038 mm(0.001 to 0.0015 in.) are recommended and will gen-
erally provide the best surface finish.
Be sure the drum is securely mounted in the lathe
before machining operations. A damper strap should
always be used around the drum to reduce vibration
and avoid chatter marks.
The maximum allowable diameter of the drum
braking surface is stamped or cast into the drum
outer edge.
CAUTION: Replace the drum if machining will cause
the drum to exceed the maximum allowable diame-
ter.
SUPPORT PLATE
REMOVAL
REMOVAL - 198 RBI AXLE
(1) Remove wheel and tire assembly.
(2) Remove the brake drum.
(3) Remove the brake shoes.
(4) Remove parking brake cable from parking
brake lever.
(5) Compress parking brake cable retainer tabs.
Then push retainer and cable through and out of
support plate.
(6) Disconnect brake line at wheel cylinder.
(7) Remove wheel cylinder from support plate,(Re-
fer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
WHEEL CYLINDERS - REMOVAL).
(8) Remove the four bolts attaching the support
plate to axle and remove the support plate with the
axle, bearing and seal.
(9) Remove axle shaft,(Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE/AXLE SHAFTS -
REMOVAL).
REMOVAL - 8 1/4 AXLE
(1) Remove the wheel and tire assembly.
(2) Remove the brake drum.
(3) Install the brake pedal prop rod.
(4) Remove the brake shoes (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/BRAKE PADS/SHOES
- REMOVAL).
(5) Remove parking brake cable from parking
brake lever.
(6) Compress parking brake cable retainer tabs.
Then push retainer and cable through and out of
support plate.
(7) Disconnect the brake line at wheel cylinder.
(8) Remove the wheel cylinder from the support
plate,(Refer to 5 - BRAKES/HYDRAULIC/MECHAN-
ICAL/WHEEL CYLINDERS - REMOVAL).
KJBRAKES - BASE 5 - 27
FLUID (Continued)
(9) Remove the axle shaft, (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/REAR AXLE - 8 1/4/AXLE
SHAFTS - REMOVAL).
(10) Remove the bolts attaching the support plate
to the axle and remove the support plate (Fig. 43).
INSTALLATION
INSTALLATION - 198 RBI AXLE
(1) Install the support plate on the axle flange.
Tighten 75 N´m (55 ft. lbs.)
(2) Install the axle, bearing and seal into the hous-
ing and tighten the four attaching bolts to 61 N´m
(45 ft. lbs.).
(3) Install the wheel cylinder,(Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/WHEEL
CYLINDERS - INSTALLATION).
(4) Install the brake line in the wheel cylinder.
(5) Install the parking brake cable in the support
plate.
(6) Connect parking brake cable to lever on sec-
ondary shoe and install brake shoes on support plate.
(7) Adjust the brake shoes to the drum with the
brake gauge.
(8) Install the brake drum and wheel and tire
assembly (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(9) Bleed brake system,(Refer to 5 - BRAKES -
STANDARD PROCEDURE) OR (Refer to 5 -
BRAKES - STANDARD PROCEDURE).
INSTALLATION - 8 1/4 AXLE
(1) Install the support plate on the axle flange.
Tighten attaching bolts to 61 N´m (45 ft. lbs.) (Fig.
43).(2) Install the wheel cylinder,(Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/WHEEL
CYLINDERS - INSTALLATION).
(3) Install the brake line in the wheel cylinder and
tighten the line to 14 N´m (124 in.lbs.)..
(4) Remove the brake pedal prop rod.
(5) Install the parking brake cable in the support
plate.
(6) Install the axle shaft, (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE - 8 1/4/AXLE
SHAFTS - INSTALLATION).
(7) Connect the parking brake cable to the lever on
the primary shoe and install the brake shoes on the
support plate (Refer to 5 - BRAKES/HYDRAULIC/
MECHANICAL/BRAKE PADS/SHOES - INSTALLA-
TION).
(8) Adjust the brake shoes to the drum with the
brake gauge (Refer to 5 - BRAKES/HYDRAULIC/
MECHANICAL/BRAKE PADS/SHOES - ADJUST-
MENTS).
(9) Install the brake drum.
(10) Install the wheel and tire assembly (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(11) Bleed the brake system,(Refer to 5 - BRAKES
- STANDARD PROCEDURE).
WHEEL CYLINDERS
REMOVAL
(1) Remove wheel and tire assembly.
(2) Remove brake drum.
(3) Install brake pedal prop rod.
(4) Disconnect wheel cylinder brake line.
(5) Remove brake shoe return springs and move
shoes out of engagement with cylinder push rods.
(6) Remove cylinder attaching bolts and remove
cylinder from support plate (Fig. 44).
DISASSEMBLY
(1) Remove push rods and boots (Fig. 45).
(2) Press pistons, cups and spring and expander
out of cylinder bore.
(3) Remove bleed screw.
CLEANING
Clean the cylinder and pistons with clean brake
fluid or brake cleaner only. Do not use any other
cleaning agents.
Dry the cylinder and pistons with compressed air.
Do not use rags or shop towels to dry the cylinder
components. Lint from cloth material will adhere to
the cylinder bores and pistons.
Fig. 43 SUPPORT PLATE 8 1/4
1 - SUPPORT PLATE
2 - MOUNTING NUTS
5 - 28 BRAKES - BASEKJ
SUPPORT PLATE (Continued)