2002 JEEP LIBERTY ENGINE ASSEMBLY

FRONT AXLE - 186FIA
TABLE OF CONTENTS
page page
FRONT AXLE - 186FIA
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - AXLE..........20
REMOVAL.............................24
INSTALLATION.........................24
ADJUSTMENTS........................25
SPECIFICATIONS - FRONT AXLE...........33
SPECIAL TOOLS
FRONT AXLE........................34
AXLE SHAFTS
REMOVAL.............................37
INSTALLATION.........................37
AXLE SHAFT SEALS
REMOVAL.............................37
INSTALLATION.........................38
AXLE BEARINGS
REMOVAL.............................38INSTALLATION.........................38
PINION SEAL
REMOVAL.............................38
INSTALLATION.........................39
DIFFERENTIAL
REMOVAL.............................40
DISASSEMBLY.........................41
ASSEMBLY............................41
INSTALLATION.........................42
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................43
INSTALLATION.........................44
PINION GEAR/RING GEAR
REMOVAL.............................44
INSTALLATION.........................46
FRONT AXLE - 186FIA
DESCRIPTION
The 186FIA (Model 30) axle consists of an alumu-
num center section with an axle tube extending from
one side. The tube is pressed into the differential
housing. The integral type housing, hypoid gear
design has the centerline of the pinion set below the
centerline of the ring gear.
The differential case is a one-piece design. The differ-
ential pinion mate shaft is retained with a roll-pin. Dif-
ferential bearing preload and ring gear backlash is
adjusted by the use of shims (select thickness). The
shims are located between the differential bearing cups
and the axle housing. Pinion bearing preload is set and
maintained by the use of a collapsible spacer.
The power is transferred from the axle through two
constant velocity (C/V) drive shafts to the wheel hubs.
The differential cover provides a means for inspec-
tion and service without removing the axle from the
vehicle. The cover has a vent tube used to relieve
internal pressure caused by vaporization and inter-
nal expansion.
OPERATION
The axle receives power from the transfer case through
the front propeller shaft. The front propeller shaft is con-
nected to the pinion gear which rotates the differential
through the gear mesh with the ring gear bolted to thedifferential case. The engine power is transmitted to the
axle shafts through the pinion mate and side gears. The
side gears are splined to the axle 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. 1).
Fig. 1 DIFFERENTIAL-STRAIGHT AHEAD DRIVING
1 - STRAIGHT AHEAD DRIVING
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
KJFRONT AXLE - 186FIA 3 - 19

REAR AXLE-81/4
TABLE OF CONTENTS
page page
REAR AXLE-81/4
DESCRIPTION.........................86
OPERATION...........................86
DIAGNOSIS AND TESTING - AXLE..........88
REMOVAL.............................91
INSTALLATION.........................91
ADJUSTMENTS........................92
SPECIFICATIONS
REAR AXLE..........................98
SPECIAL TOOLS
8 1/4 AXLE..........................98
AXLE SHAFTS
REMOVAL............................101
INSTALLATION........................101
AXLE SHAFT SEALS
REMOVAL............................101
INSTALLATION........................102
AXLE BEARINGS
REMOVAL............................102
INSTALLATION........................102PINION SEAL
REMOVAL............................102
INSTALLATION........................103
DIFFERENTIAL
REMOVAL............................104
DISASSEMBLY........................105
ASSEMBLY...........................105
INSTALLATION........................105
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT....106
DISASSEMBLY........................107
CLEANING...........................109
INSPECTION.........................109
ASSEMBLY...........................109
DIFFERENTIAL CASE BEARINGS
REMOVAL............................110
INSTALLATION........................110
PINION GEAR/RING GEAR/TONE RING
REMOVAL............................110
INSTALLATION........................112
REAR AXLE-81/4
DESCRIPTION
The axle housings consist of a cast iron center sec-
tion with axle tubes extending from either side. The
tubes are pressed into and welded to the differential
housing to form a one-piece axle housing. The axles
are equipped with semi-floating axle shafts, meaning
vehicle loads are supported by the axle shaft and
bearings. The axle shafts are retained by C-locks in
the differential side gears.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a
threaded pin. Differential bearing preload and ring
gear backlash are set and maintained by threaded
adjusters at the outside of the differential housing.
Pinion bearing preload is set and maintained by the
use of a collapsible spacer.
The differential cover provides a means for inspec-
tion and service without removing the complete axlefrom the vehicle. A vent hose is used to relieve inter-
nal pressure caused by lubricant vaporization and
internal expansion.
Axles equipped with a Trac-Loktdifferential are
optional. A differential has a one-piece differential
case, and the same internal components as a stan-
dard differential, plus two clutch disc packs.
OPERATION
The axle receives power from the transmission/
transfer case through the rear propeller shaft. The
rear propeller shaft is connected to the pinion gear
which rotates the differential through the gear mesh
with the ring gear bolted to the differential case. The
engine power is transmitted to the axle shafts
through the pinion mate and side gears. The side
gears are splined to the axle shafts.
3 - 86 REAR AXLE-81/4KJ

(4) Position the tube in the flaring tool flush with
the top of the tool bar (Fig. 3). Then tighten the tool
bar on the tube.
(5) Install the correct size adaptor on the flaring
tool yoke screw.
(6) Lubricate the adaptor.
(7) Align the adaptor and yoke screw over the tube
(Fig. 3).
(8) Turn the yoke screw in until the adaptor is
squarely seated on the tool bar.
REMOVAL
REMOVAL - FRONT HOSE
(1) Install prop rod on the brake pedal to keep
pressure on the brake system.
(2) Remove the brake line from the brake hose
inside the engine compartment by the front control
arm bolt (Fig. 4).
(3) Raise and support vehicle.
(4) Remove the brake hose banjo bolt at the cali-
per.
(5) Remove the mounting bolt for the top of the
brake hose at the vehicle (Fig. 5).
(6) Remove the hose.
REMOVAL - REAR BRAKE HOSE
(1) Install prop rod on the brake pedal to keep
pressure on the brake system.
(2) Raise and support the vehicle.
(3) Remove the brake line from the hose at the
body (Fig. 6).
(4) Remove the brake hose mounting bolt at the
top of the hose located at the body (Fig. 6).
(5) Remove the vent tube (Fig. 7).
(6) Remove the two brake lines at the bottom of
the hose located at the axle (Fig. 7).
(7) Remove the mounting bolt for the brake hose
at the axle (Fig. 7).
(8) Remove the hose.
Fig. 3 ISO Flaring
1 - ADAPTER
2 - LUBRICATE HERE
3 - PILOT
4 - FLUSH WITH BAR
5 - TUBING
6 - BAR ASSEMBLY
Fig. 4 INNER FENDER BRAKE LINE
1 - GROMMET
2 - BRAKE LINE
Fig. 5 FRONT BRAKE HOSE
1 - TOP OF FRONT BRAKE HOSE
2 - WHEEL SPEED SENSOR WIRE
3 - UPPER CONTROL ARM
KJBRAKES - BASE 5 - 9
BRAKE LINES (Continued)

POWER BRAKE BOOSTER
DESCRIPTION
The booster assembly consists of a housing divided
into separate chambers by two internal diaphragms.
The outer edge of each diaphragm is attached to the
booster housing. The diaphragms are connected to
the booster primary push rod.
Two push rods are used in the booster. The pri-
mary push rod connects the booster to the brake
pedal. The secondary push rod connects the booster
to the master cylinder to stroke the cylinder pistons.
OPERATION
The atmospheric inlet valve is opened and closed
by the primary push rod. Booster vacuum supply is
through a hose attached to an intake manifold fitting
at one end and to the booster check valve at the
other. The vacuum check valve in the booster housing
is a one-way device that prevents vacuum leak back.
Power assist is generated by utilizing the pressure
differential between normal atmospheric pressure
and a vacuum. The vacuum needed for booster oper-
ation is taken directly from the engine intake mani-
fold. The entry point for atmospheric pressure is
through a filter and inlet valve at the rear of the
housing (Fig. 33).
The chamber areas forward of the booster dia-
phragms are exposed to vacuum from the intake
manifold. The chamber areas to the rear of the dia-
phragms, are exposed to normal atmospheric pres-
sure of 101.3 kilopascals (14.7 pounds/square in.).Brake pedal application causes the primary push
rod to open the atmospheric inlet valve. This exposes
the area behind the diaphragms to atmospheric pres-
sure. The resulting pressure differential provides the
extra apply force for power assist.
The booster check valve, check valve grommet and
booster seals are serviceable.
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.
(2) Stop engine and shift transmission into Neu-
tral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leak-
age).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Pro-
ceed to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off igni-
tion to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vac-
uum assisted pedal applications. If vacuum assist is
not provided, booster is faulty.
POWER BOOSTER VACUUM TEST
(1) Connect vacuum gauge to booster check valve
with short length of hose and T-fitting (Fig. 34).
(2) Start and run engine at curb idle speed for one
minute.
(3) Observe the vacuum supply. If vacuum supply
is not adequate, repair vacuum supply.
(4) Clamp hose shut between vacuum source and
check valve.
(5) Stop engine and observe vacuum gauge.
(6) If vacuum drops more than one inch Hg (33
millibars) within 15 seconds, booster diaphragm or
check valve is faulty.
POWER BOOSTER CHECK VALVE TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster.
(3) Use a hand operated vacuum pump for test.
Fig. 32 BOOSTER PUSH ROD
1 - MASTER CYLINDER ASSEMBLY
2 - BRAKE BOOSTER
3 - CLIP
4 - BRAKE PEDAL
5 - BOOSTER ROD
KJBRAKES - BASE 5 - 21
PEDAL (Continued)

(4) Tighten booster mounting nuts to 22.6 N´m
(200 ft. lbs.).
(5) Install the knee blocker,(Refer to 23 - BODY/
INSTRUMENT PANEL/KNEE BLOCKER - INSTAL-
LATION).
(6) If original master cylinder is being installed,
check condition of seal at rear of master cylinder.
Replace seal if cut, or torn.
(7) Clean cylinder mounting surface of brake
booster. Use shop towel wetted with brake cleaner for
this purpose. Dirt, grease, or similar materials will
prevent proper cylinder seating and could result in
vacuum leak.
(8) Align and install master cylinder on the
booster studs. Install mounting nuts and tighten to
22.6 N´m (200 in. lbs.).
(9) Connect vacuum hose to booster check valve.
(10) Remount the HCU. Tighten bracket mounting
nuts to 22.6 N´m (200 in. lbs.).
(11) Connect and secure the brake lines to HCU or
junction block and master cylinder. Start all brake
line fittings by hand to avoid cross threading.
(12) Connect the wire to fluid level switch at the
bottom of the reservoir.
(13) Fill and bleed base brake system,(Refer to 5 -
BRAKES - STANDARD PROCEDURE).
(14) Verify proper brake operation before moving
vehicle.
MASTER CYLINDER
DESCRIPTION
The master cylinder has a removable nylon reser-
voir. The cylinder body is made of aluminum and
contains a primary and secondary piston assembly.
The cylinder body including the piston assemblies
are not serviceable. If diagnosis indicates an internal
problem with the cylinder body, it must be replaced
as an assembly. The reservoir and grommets are the
only replaceable parts on the master cylinder.
OPERATION
The master cylinder bore contains a primary and
secondary piston. The primary piston supplies
hydraulic pressure to the front brakes. The secondary
piston supplies hydraulic pressure to the rear brakes.
The master cylinder reservoir stores reserve brake
fluid for the hydraulic brake circuits.
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.(2) Stop engine and shift transmission into Neu-
tral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leak-
age).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Pro-
ceed to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off igni-
tion to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vac-
uum assisted pedal applications. If vacuum assist is
not provided, booster is faulty.
POWER BOOSTER VACUUM TEST
(1) Connect vacuum gauge to booster check valve
with short length of hose and T-fitting (Fig. 38).
(2) Start and run engine at curb idle speed for one
minute.
(3) Observe the vacuum supply. If vacuum supply
is not adequate, repair vacuum supply.
(4) Clamp hose shut between vacuum source and
check valve.
(5) Stop engine and observe vacuum gauge.
(6) If vacuum drops more than one inch HG (33
millibars) within 15 seconds, booster diaphragm or
check valve is faulty.
POWER BOOSTER CHECK VALVE TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster.
(3) Use a hand operated vacuum pump for test.
(4) Apply 15-20 inches vacuum at large end of
check valve (Fig. 39).
(5) Vacuum should hold steady. If gauge on pump
indicates vacuum loss, check valve is faulty and
should be replaced.
STANDARD PROCEDURE - MASTER CYLINDER
BLEEDING
A new master cylinder should be bled before instal-
lation on the vehicle. Required bleeding tools include
bleed tubes and a wood dowel to stroke the pistons.
Bleed tubes can be fabricated from brake line.
(1) Mount master cylinder in vise.
5 - 24 BRAKES - BASEKJ
POWER BRAKE BOOSTER (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)

CLUTCH DISC
REMOVAL
(1) Remove transmission.
(2) Mark position of pressure plate on flywheel
with paint or a scriber for assembly reference, if
clutch is not being replaced.
(3) Loosen pressure plate bolts evenly and in rota-
tion to relieve spring tension and avoid warping the
plate.
(4) Remove pressure plate bolts and pressure plate
and disc.
INSTALLATION
(1) Lightly scuff sand flywheel face with 180 grit
emery cloth, then clean with a wax and grease
remover.
(2) Lubricate pilot bearing with Mopar high tem-
perature bearing grease or equivalent.
(3) Check runout and operation ofnewclutch disc.
NOTE: Disc must slide freely on transmission input
shaft splines.
(4) With the disc on the input shaft, check face
runout with dial indicator. Check runout at disc hub
6 mm (1/4 in.) from outer edge of facing. Obtain
another clutch disc if runout exceed 0.5 mm (0.020
in.).
(5) Position clutch disc on flywheel with side
marked flywheel against the flywheel.
NOTE: If not marked, the flat side of disc hub goes
towards the flywheel on the 3.7L engine and
towards the transmission on 2.4L engine.
(6) Insert clutch alignment tool through the clutch
disc and into the pilot bearing (Fig. 1).
(7) Position clutch pressure plate over disc and on
the flywheel (Fig. 1).
(8) Install pressure plate bolts finger tight.
CAUTION: Use only the factory bolts to mount the
pressure plate. The bolts must be the correct size.
If bolts are too short, there isn't enough thread
engagement, if too long bolts interfere with the Dual
Mass Flywheel.
(9) Tighten pressure plate bolts evenly and in rota-
tion a few threads at a time.
CAUTION: The bolts must be tightened evenly and
to specified torque to avoid distorting the pressure
plate.(10) Tighten pressure plate bolts to 31 N´m (23 ft.
lbs.) on 2.4L engines and 50 N´m (37ft. lbs.) on 3.7L
engines.
(11) Apply light coat of Mopar high temperature
bearing grease or equivalent to clutch disc hub and
splines of transmission input shaft.
CAUTION: Do not over lubricate shaft splines. This
will result in grease contamination of disc.
(12) Install transmission.
CLUTCH RELEASE BEARING
REMOVAL
(1) Remove transmission.
(2) Disconnect release bearing from release lever
and remove the bearing (Fig. 2).
(3) Inspect bearing slide surface of transmission
front bearing retainer. Replace retainer if slide sur-
face is scored, worn, or cracked.
(4) Inspect release fork and fork pivot. Be sure
pivot is secure and in good condition. Be sure fork is
not distorted or worn. Replace release fork retainer
spring if bent or damaged.
INSTALLATION
(1) Lubricate crankshaft pilot bearing with Mopar
high temperature bearing grease or equivalent. Apply
grease to end of long shank, small diameter flat
blade screwdriver. Then insert tool through clutch
disc hub to reach bearing.
Fig. 1 ALIGNING CLUTCH DISC
1 - FLYWHEEL
2 - PRESSURE PLATE
3 - CLUTCH DISC ALIGNMENT TOOL
6 - 6 CLUTCHKJ

(9) Slide actuator off pivot pin.
(10) Disconnect clutch interlock safety switch
wires.(11) Remove clutch hydraulic linkage through
engine compartment.
INSTALLATION
NOTE: The clutch master cylinder, slave cylinder
and connecting line are serviced as an assembly
only. The linkage components cannot be over-
hauled or serviced separately. The cylinders and
connecting line are sealed units.
(1) Be sure reservoir cover on clutch master cylin-
der is tight to avoid spills.
(2) Position clutch linkage components in vehicle.
Work connecting line and slave cylinder downward
past engine and adjacent to clutch housing.
(3) Position clutch master cylinder on dash panel.
(4) Attach clutch master cylinder actuator to pivot
pin on clutch pedal.
(5) Install and tighten clutch master cylinder
attaching nuts to 38 N´m (28 ft. lbs.).
(6) Raise vehicle.
(7) Insert slave cylinder push rod through clutch
housing opening and into release lever. Be sure cap
on end of rod is securely engaged in lever. Check this
before installing cylinder attaching nuts.
(8) Install and tighten slave cylinder attaching
nuts to 23 N´m (17 ft. lbs.).
(9) Secure clutch fluid line in body and transmis-
sion clips.
(10) Lower vehicle.
(11) Connect clutch interlock safety switch wires.
MASTER CYLINDER
INSPECTION
The clutch fluid reservoir, master cylinder, slave
cylinder and fluid lines are pre-filled with fluid at
the factory during assembly operations.
The hydraulic system should not require additional
fluid under normal circumstances.The reservoir
fluid level will actually increase as normal
clutch wear occurs. Avoid overfilling or remov-
ing fluid from the reservoir.
Clutch fluid level is checked at the master cylinder
reservoir. An indicator ring is provided on the outside
of the reservoir. With the cap and diaphragm
removed, fluid level should not be above indicator
ring.
To avoid contaminating the hydraulic fluid during
inspection, wipe reservoir and cover clean before
removing the cap.
Fig. 6 SLAVE CYLINDER
1 - CLUTCH SLAVE CYLINDER
Fig. 7 CLUTCH PEDAL
1 - CYLINDER
2 - ACTUATOR SHAFT
3 - ACTUATOR EYE
4 - PEDAL PIN
5 - CONNECTOR
KJCLUTCH 6 - 9
LINKAGE (Continued)