1988 JEEP CHEROKEE Service Repair Manual

Removal & Installation
Remove and disassemble instrument cluster. Remove
speedometer, tachometer, or gauge being serviced. To install, reverse
removal procedure.

JA C KIN G & H O IS TIN G

1988 J e ep C hero ke e
1988 Jacking & Hoisting
JEEP
HOISTING
FRAME CONTACT HOIST
Cherokee, Comanche, Wagoneer & Wrangler
Vehicle may be raised on single or twin-post swiveling arm
or ramp-type drive hoists. If using swiveling arm hoist, ensure
lifting pads are positioned evenly on frame rails at points "A" and
"B". Ensure lifting pads are not contacting transfer case or skid
plate. All hoists should be equipped with proper adapters to support
vehicle at frame rails only.
Grand Wagoneer
Vehicle may be raised on single or twin-post swiveling arm
or ramp-type drive hoists. If using swiveling arm hoist, ensure
lifting pads are positioned evenly on frame rails and lifting pads
are not contacting transfer case or skid plate. All hoists should be
equipped with proper adapters to support vehicle at frame rails only.
JACKING
FLOOR JACK
Cherokee, Comanche, Wagoneer & Wrangler
Vehicle may be raised by positioning jack at points "A" and
"B" only. Never attempt to raise the vehicle with the jack positioned
under the axle tubes, body side sills or front suspension arms. Use
the sub frame rail lift points only.
Grand Wagoneer
Vehicle may be raised by positioning jack under the front or
rear frame rails. Never place jack under front or rear axle tubes, or
under shock absorber mounting brackets.
Fig. 1: Hoisting & Jacking Points
Position lifting pads evenly on frame rails.

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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

Removal
1) Raise and support vehicle. Drain shift housing fluid.
Disconnect vacuum harness. Remove housing bolts. Remove motor and
housing. Mark shift fork and housing for reassembly. See Fig. 3.
2) Rotate shift motor. Remove shift fork and motor snap
rings. Remove shift motor from housing. Remove "O" ring from motor.
Always use a new "O" ring for reassembly.
Installation
Install new "O" ring on motor shaft. Install motor into
housing and slide shift fork onto shaft. Position motor and housing on
axle. Add axle lubricant to shift motor housing. Install shift fork in
shift collar and install housing bolts. Connect all vacuum harnesses
to motor.
Fig. 3: Shift Motor & Housing

MAIN TE N AN CE IN FO RM ATIO N

1988 J e ep C hero ke e
1984-88 MAINTENANCE
AMC/Jeep Maintenance Information
Jeep; Cherokee,
Wagoneer
* PLEASE READ THIS FIRST *
NOTE: For scheduled maintenance intervals and the related fluid
capacities, fluid specifications and labor times for major
service intervals, see SCHEDULED SERVICES article below:
* SCHEDULED SERVICES - GASOLINE
* SCHEDULED SERVICES - DIESEL ENGINES - NORMAL (1985-87)
Warranty information and specifications for fluid
capacities, lubrication specifications, wheel and tire size,
and battery type are covered in this article.
MODEL IDENTIFICATION
VIN LOCATION
The Vehicle Identification Number (VIN) is located on the
left side of the dash panel at the base of the windshield. The VIN
chart explains the code characters.
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 * American Motors/Jeep
3 - Type
C * Multi-Purpose Vehicle
D * Incomplete Vehicle
E * Export, LHD
F * Export, RHD
4 - Engine Type
B * 2.1L (128 CID) 4-Cylinder Turbo (Diesel) (001B) (1985-87)
H * 2.5L (150 CID) 4-Cylinder TBI (Gasoline) (001H) (1986-88)
U * 2.5L (150 CID) 4-Cylinder 1-Bbl. (Gasoline) (001U) (1984-85)
Y * 2.5L (150 CID) 4-Cylinder 1-Bbl. (Export) (001Y) (1984-85)
W * 2.8L (171 CID) V6 2-Bbl. (Gasoline) (001W) (1984-86)
M * 4.0L (242 CID) I-6 (Gasoline) (001M) (1987-88)

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)

* Cold Climate Operation
* Towing Or Heavily Loading
* Severe Dust Conditions
* Sustained High Speed Operation
* Off-Road Driving
* Hot Weather, Stop-And-Go Driving
* Extensive Idling Conditions (Taxi Or Delivery Type Service)
Normal Service
* Driven More Than 10 Miles Daily
* No Severe Service Operating Conditions
CAMSHAFT TIMING BELT REPLACEMENT INFORMATION (TURBO-DIESEL)
CAUTION: Failure to replace a faulty camshaft timing belt may result
in serious engine damage.
The condition of camshaft drive belts should always be
checked on vehicles which have more than 50,000 miles. Although some
manufacturers do not recommend belt replacement at a specified
mileage, others require it at 60,000-100,000 miles. A camshaft drive
belt failure may cause extensive damage to internal engine components
on most engines, although some designs do not allow piston-to-valve
contact. These designs are often called "Free Wheeling".
Many manufacturers changed their maintenance and warranty
schedules in the mid-1980's to reflect timing belt inspection and/or
replacement at 50,000-60,000 miles. Most service interval schedules
reflect these changes.
Belts or components should be inspected and replaced if any
of the following conditions exist:
* Cracks Or Tears In Belt Surface
* Missing, Damaged, Cracked Or Rounded Teeth
* Oil Contamination
* Damaged Or Faulty Tensioners
* Incorrect Tension Adjustment
SERVICE LABOR TIMES
SERVICE LABOR TIMES TABLE (HOURS)








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( 1) 30,000 60,000
Application Mile Service Mile Service
2.1L (Turbo Diesel)
Automatic Transmission ........... 4.3 ................ 4.5
Manual Transmission .............. 3.6 ................ 3.8
2.5L
Automatic Transmission ........... 5.6 ................ 3.5
Manual Transmission .............. 4.9 ................ 3.5
2.8L
Automatic Transmission ........... 5.8 ................ 3.7
Manual Transmission .............. 5.1 ................ 3.7
4.0L
Automatic Transmission ........... 5.7 ................ 3.6
Manual Transmission .............. 5.0 ................ 3.6
( 1) - Add .8 hr. for vehicles equipped with 4WD.









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