4WD JEEP CHEROKEE 1988 Service Repair Manual

CLU TC H

1988 J e ep C hero ke e
1988 Clutch
Hydraulic
Cherokee, Comanche, Wagoneer, Wrangler
DESCRIPTION
The clutch assembly consists of a single dry-disc driven
plate and a one-piece diaphragm spring-type clutch cover. On Wrangler
4-cylinder models, the clutch cover and driven plate diameter is 9.28"
(232 mm). On Wrangler 6-cylinder models, the clutch cover and driven
plate diameter is 10.5" (266 mm). On all other 4 and 6-cylinder
models, the clutch cover and driven plate diameter is 9.7"
(246 mm). The clutch is actuated through a hydraulic master cylinder
and slave cylinder.
On Wrangler models, the slave cylinder is mounted inside the
clutch housing. The bearing is permanently attached to the cylinder
piston.
TRANSMISSION APPLICATION









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Vehicle Model Transmission Model
Cherokee, Comanche, Wagoneer ........... Aisin AX4 4-Speed
Aisin AX5 5-Speed O/D
Wrangler ........................... Aisin AX5 5-Speed O/D
Peugeot BA 10/5 5-Speed O/D









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REMOVAL & INSTALLATION
TRANSMISSION
Removal
1) Remove the shift knob and lock nut from transmission and
transfer case shift levers (if equipped). On Wrangler models, remove
screws attaching transmission and transfer case shift lever boots and
remove both boots.
2) On all other models, raise outer gearshift lever boot and
remove upper part on center console. Remove lower part of console,
remove inner boot and gearshift lever.
3) On Wrangler models, remove transmission shift tower dust
cover. Remove transmission shift lever and stub shaft. DO NOT remove
shift lever from stub shaft.
4) On all models, raise and support vehicle. Drain
transmission lubricant. Mark rear drive shaft for reassembly and
remove rear drive shaft. Support transmission assembly and remove
crossmember. Disconnect speedometer cable and wiring from back-up
light switch.
5) On 4WD models, drain transfer case lubricant. Disconnect
transfer case vacuum hoses and linkage. Tag vacuum hoses for
reassembly. Disconnect front drive shaft and secure out of way.
6) On all models, remove clutch slave cylinder. Position
transmission jack under transmission assembly. Remove bolts securing
clutch housing to engine and remove transmission assembly. Remove
throw-out lever, bearing, and pivot ball from clutch housing.
Installation
To install, reverse removal procedure.

Fig. 2: Exploded View of Split Case (4-Pinion)
2) Drive vehicle over formica board until one rear wheel is
in the center of board and paper. Place a block of wood 2" high and a
minimum of 3" wide in front of one of the front wheels.
3) Open throttle gradually attempting to slowly drive vehicle
over block of wood. If paper slips out of position, reposition paper
and repeat test. If vehicle drives over block of wood, axle is
functioning properly.
DANA 4-PINION POWER-LOK
1) With engine off and transmission in "N", raise one wheel
off ground. Block both front and rear wheels of opposite side. Install
adapter tool across 2 wheel studs and attach torque wrench to center
of tool.
2) Observe torque required to continuously turn wheel
smoothly through several revolutions. Repeat test for opposite side.
If differential is okay, torque should be 40-200 ft. lbs. (54-272 N.
m). Disregard breakaway torque. Use rotating torque only.
NOTE: Exploded view of Chrysler Motors Trac-Lok differential was
not available from manufacturer.
REMOVAL & INSTALLATION
See DANA SEMI-FLOATING or FULL-FLOATING AXLE article in this
section.
OVERHAUL
DANA 2-PINION TRAC-LOK
NOTE: For front axle shaft and bearing removal, see articles on
DANA FULL-FLOATING AXLES or 4WD STEERING KNUCKLES in this
section. With the exception of ring gear and differential
side bearings, Chrysler Motors does not recommend disassembly
of differential. If repair is required, manufacturer
recommends replacing entire unit as an assembly.
Disassembly (Jeep)
1) Using 2 screwdrivers, remove pinion snap rings. Using a
brass drift and a hammer, remove pinion shaft from case. Install Step

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DRIV E A XLE - F U LL F LO ATIN G

1988 J e ep C hero ke e
Drive Axles - Dana Full-Floating Axles
Jeep Front & Rear Drive Axles
DESCRIPTION
The axle assembly is an integral carrier type with hypoid
gear ring and pinion. Stamped steel cover is removable for inspection
and repair of differential. Vehicle loads are carried by axle
housings. Axle shafts of "full-floating" rear assemblies may be
removed without disturbing wheel bearings.
Drive pinion depth, pinion bearing preload and differential
side bearing preload are all set by shims.
See LOCKING HUB and 4WD STEERING KNUCKLE articles in this
section for removal and installation procedures for these front drive
axle component parts.
AXLE RATIO & IDENTIFICATION
A metal tag on axle is stamped with gear ratio, part numbers
and limited slip identification. To determine drive axle ratio, refer
to MODEL IDENTIFICATION BY RING GEAR SIZE table.
MODEL IDENTIFICATION BY RING GEAR SIZE









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Model Ring Gear Diameter
44 ....................................... 8.50"
60 ....................................... 9.75"
61 ....................................... 9.75"
70 ...................................... 10.50"
80 ...................................... 11.25"









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FRONT HUB, BEARING, SPINDLE & AXLE SHAFT R & I
FRONT HUB BEARING ADJUSTING SPECIFICATIONS








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Application ( 1) Ft. Lbs. (N.m)
Adjusting Nut
Step 1 ............................... 50 (68)
Step 2 .......................... Back Off 20

Lock Nut ............................... 50 (68)
( 1) - While Rotating Hub.









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REMOVAL (CHEROKEE, COMANCHE & WAGONEER)
1) Raise and support vehicle. Remove tire and wheel assembly.
Remove disc brake caliper and support out of way.
2) Match mark disc rotor and hub and remove disc rotor.
Remove cotter pin, nut lock and axle hub nut. Remove hub-to-knuckle
bolts. Pull hub assembly off axle shaft. Pull axle shaft through
knuckle to remove. Inspect axle shaft "U" joint and shaft splines for
wear. Replace as necessary.
3) Press hub out of bearings. Remove seals and bearings.

DRIV E S H AFT A LIG NM EN T

1988 J e ep C hero ke e
1988 Drive Shafts Alignment
DESCRIPTION
Drive shafts are balanced, one-piece, tubular shafts with
universal joints at each end. Number used in vehicle varies: one
shaft, 2 shafts with a center bearing, or 3 shafts. Three shafts are
used in many 4WD applications. Location of slip joints varies with
model and manufacturer. See Fig. 1.
Fig. 1: View of 5 Commonly Used Drive Shaft Combinations
Many 4WD models use 3 drive shafts.
INSPECTION

WOT Switch On bracket, with ISA motor.
4WD Indicator Light Switch In right rear corner of engine
compartment.









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A - E N G IN E/V IN ID

1988 J e ep C hero ke e
1984-89 ENGINE PERFORMANCE
Chrysler Motors/Jeep VIN Code Identification
Jeep; Cherokee, Wagoneer
MODEL IDENTIFICATION
VIN CODE LOCATION
The Vehicle identification number (VIN) is located on the
left side of the dash panel at the base of the windshield.
VIN CODE ID EXPLANATION
Numbers preceding the explanations in the legend below refer
to the sequence of characters as listed on VIN identification label.
See VIN example below.








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(VIN) 1 J C U N 7 7 1 X G T 0 0 0 0 0 1 


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 










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1 - Manufacturing Country
1
* United States
2 - Company/Make
J * Chrysler Motors/Jeep
3 - Type (1984-88)
C * Multi-Purpose Vehicle
D * Incomplete Vehicle
3 - Type (1989)
3 * Multi-Purpose Vehicle
6 * Incomplete Vehicle
7 * Truck
4 - Engine Type (1984-88)
B * 2.1L (128 Cu. In.) 4-Cylinder Turbo (Diesel)
H * 2.5L (150 Cu. In.) 4-Cylinder TBI (Gasoline)
U * 2.5L (150 Cu. In.) 4-Cylinder 1 Bbl. (Gasoline)
W * 2.8L (171 Cu. In.) V6 2 Bbl. (Gasoline)
M * 4.0L (242 Cu. In.) 6-Cylinder (Gasoline)
4 - GVWR (1989)
E * 3001-4000
F * 4001-5000
G * 5001-6000
H * 6001-7000
5 - Transmission/(Transfer Case) (1984-88)
L * 5-Speed Manual Floor Shift (Part Time 4WD)
X * 4-Speed Manual Floor Shift (Part Time 4WD)
B * Auto Floor Shift (Part Time 4WD)
C * Auto Floor Shift (Full Time 4WD)
E * Auto Column Shift (Part Time 4WD)
J * Auto Column Shift (Full Time 4WD)
A * Auto Column Shift (2WD)

S * 4-Speed Manual Floor Shift (2WD)
D * Auto Floor Shift (2WD)
W * 5-Speed Manual Shift (2WD)
5 - Car Line (1989)
J * Cherokee 4WD
N * Wagoneer 4WD
T * Cherokee 2WD
6 - Body Style (4WD) (1984-88)
75 * Wagoneer Wagon 4-Door
77 * Cherokee Wagon 2-Door
78 * Cherokee Wagon 4-Door
6 - Series (1989)
2 * Base (L)
3 * Pioneer (M)
5 * Laredo (P)
7 * Limited (X)
7 - Body Style (2WD) (1984-1988)
73 * Cherokee Wagon 2-Door
74 * Cherokee Wagon 4-Door
7 - Body Style (1989)
5 * 4-Door Wagon
7 * 2-Door Wagon
8 * 4-Door Wagon
8 - Trim Package (1984-88)
1 * Custom
2 * Pioneer
3 * Chief
4 * Laredo
5 * Wagoneer
6 * Limited
K * Cherokee Base (2WD)
L * Pioneer (2WD)
M * Laredo (2WD)
8 - Engine (1989)
E * 2.5L
L * 4.0L
P * 2.5L
S * 4.0L
9 - Check Digit
* Manufacturer Assigned
10 - Model Year
E * 1984
F * 1985
G * 1986
H * 1987
J * 1988
K * 1989
11 - Assembly Plant
J * Brampton, Ontario, Canada
L * Toledo, Ohio Plant No. 1
P * Toledo, Ohio Plant No. 2
T * Toledo, Ohio

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LO CKIN G H UBS - A U TO M ATIC

1988 J e ep C hero ke e
1988 Locking Hubs - Command-Trac & Selec-Trac
Jeep
DESCRIPTION & OPERATION
Command-Trac locking hub is used on Model 30 front axles.
This system can be shifted between 2WD and 4WD high range while
vehicle is moving. The only time vehicle must be stopped to shift into
or out of 4WD is when shifter is in low range. See Fig. 1.
Selec-Trac locking hubs allow full or part time 4WD. Used on
Model 30 front axles, system can be shifted into 2WD or 4WD modes only
when vehicle is stopped. See Fig. 2.
Fig. 1: Command-Trac Vacuum Control System
TROUBLE SHOOTING
SELEC-TRAC SYSTEM
2WD To 4WD
Position mode select switch to "4WD" position while driving
vehicle 2-3 MPH. Axle should ratchet and clunk into position. Transfer
case should shift after axle shifts, accompanied by hissing sound from
mode selector switch.
4WD To 2WD
1) Position mode select switch to "2WD" position. Transfer
case should shift to 2WD and not allow shifting into 4WD or "LO"
range. Axle should shift after transfer case shifts.

2) To determine if front axle has completed a shift out of
4WD into 2WD, position mode select switch back to "4WD" position while
operating vehicle at slow speed. If vehicle shifts into 2WD, axle will
ratchet. If shift is not completed, transfer case will shift into 4WD
and hissing sound will come from mode select switch.
FRONT AXLE SHIFT MOTOR TEST
1) Disconnect vacuum harness from front axle shift motor.
Connect vacuum pump to shift motor front port. Apply 15 in. Hg vacuum
to shift motor. Rotate right front wheel to disengage axle.
2) Shift motor should hold vacuum at least 30 seconds. If
not, replace motor. If motor does hold vacuum, disconnect vacuum pump
from shift motor front port. Connect pump to shift motor rear port and
cap transfer case connecting port. Apply 15 in. Hg vacuum to motor.
3) Shift motor should hold vacuum for at least 30 seconds. If
not, replace motor. If motor does hold vacuum, remove cap from shift
motor transfer case connecting port and check for vacuum. If no vacuum
is present, rotate right front wheel to ensure axle has shifted
completely. Axle must completely shift to open shift motor connecting
port.
4) Recheck vacuum at shift motor transfer case port. If
vacuum is present, transfer case requires diagnosis. Command-Trac uses
Model 207 transfer case. Selec-Trac uses Model 228 transfer case.
REMOVAL & INSTALLATION
LOCKING HUB
Removal
1) Remove cover to outer clutch housing. Remove bearing race
spring assembly. Remove sealing ring and seal bridge retainer. Remove
bearing components.
2) Squeeze tangs of wire retaining ring together with needle-
nose pliers. Pull remaining components of automatic hub from wheel.
Installation
1) Ensure lock ring is in position. Using Bearing Nut Wrench
(J-6893-D), tighten wheel bearing adjusting nut to 50 ft. lbs. (60 N.\
m) to seat bearings.
2) Back off nut and tighten to 35 ft. lbs. (47 N.m) while
rotating hub. Finally, back off nut a maximum of 3/8 turn. Assemble
lock ring (with tab in keyway) over axle shaft, against bearing
adjustment nut.
3) Adjustment nut pin must pass through one of the washer
holes. Tighten outer adjusting nut to 183 ft. lbs. (248 N.m). Align
outer clutch housing splines with splines of wheel hub.
4) Loosen cover screws 3 or 4 turns, and push in on cover to
allow retaining ring to expand into rotor hub groove. Tighten cover
cap screws to 40-50 INCH lbs. (4.5-5.6 N.m).
Fig. 2: Selec-Trac Vacuum Control System
AXLE SHIFT MOTOR & HOUSING

5 - Transmission/(Transfer Case)
A * Auto Column Shift (2WD)
B * Auto Floor Shift (Part Time 4WD)
C * Auto Floor Shift (Full Time 4WD)
D * Auto Floor Shift (2WD)
E * Auto Column Shift (Part Time 4WD)
J * Auto Column Shift (Full Time 4WD)
L * 5-Speed Manual Floor Shift (Part Time 4WD)
N * 5-Speed Manual Floor Shift (Full Time 4WD)
S * 4-Speed Manual Floor Shift (2WD)
W * 5-Speed Manual Shift (2WD)
X * 4-Speed Manual Floor Shift (Part Time 4WD)
6-7 - Body Style
73 * Cherokee Wagon 2-Door (2WD)
74 * Cherokee Wagon 4-Door (2WD)
75 * Wagoneer Wagon 4-Door (4WD)
77 * Cherokee Wagon 2-Door (4WD)
78 * Cherokee Wagon 4-Door (4WD)
8 - Trim Package
1 * Custom
2 * Pioneer
3 * Chief
4 * Laredo
5 * Base
5 * Wagoneer
6 * Limited
K * Cherokee Base (2WD)
L * Pioneer (2WD)
M * Laredo (2WD)
9 - Check Digit
* Manufacturer Assigned
10 - Model Year
E * 1984
F * 1985
G * 1986
H * 1987
J * 1988
11 - Assembly Plant
T * Toledo, Ohio
12-17 - Sequential Serial Number
* Production Sequence
MAINTENANCE SERVICE INFORMATION
SEVERE & NORMAL SERVICE DEFINITION
NOTE: Use the Severe Service schedule if the vehicle to be serviced
is operated under ANY (one or more) of these conditions:
Service is recommended at specified mileage intervals of
vehicle operation. Service schedules are based on the following
primary operating conditions:
Severe Service
* Short Trips (About 15 Miles)