steering wheel JEEP CHEROKEE 1988 Service Repair Manual

with manifold pressure information.
Knock Sensor
The knock (detonation) sensor, located in the cylinder head,
provides an input signal to the ECU whenever detonation occurs. The
ECU then retards ignition advance to eliminate the detonation at the
applicable cylinders.
Speed Sensor
The speed sensor (or crankshaft position sensor) is mounted
at the flywheel/drive plate housing. The sensor detects the flywheel/
drive plate teeth as they pass during engine operation and sends an
electrical signal to the ECU, which calculates engine speed.
The flywheel/drive plate has a large trigger tooth and notch
located 90
and 12 small teeth before each top dead center (TDC)
position. When a small tooth or notch pass the magnetic core in the
sensor, the build-up and collapse of the magnetic field induces a
small voltage signal in the sensor pick-up windings.
The ECU counts these signals representing the number of teeth
as they pass the sensor. When a larger trigger tooth and notch pass
the magnetic core, a higher voltage signal is sent to the ECU. This
indicates to the ECU that a piston will be at the TDC position 12
teeth later. The ECU either advances or retards ignition timing as
necessary according to sensor inputs.
Battery Voltage
Battery voltage input to the ECU ensures that proper voltage
is applied to the injector. The ECU varies voltage to compensate for
battery voltage fluctuations.
Starter Motor Relay
The engine starter motor relay provides an input to the ECU,
indicating the starter motor is engaged.
Wide Open Throttle (WOT) Switch
The WOT switch is mounted on the side of the throttle body.
The switch provides a voltage signal to the ECU under wide open
throttle conditions. The ECU responds to this signal by enriching the
air/fuel mixture delivered to the injector.
Closed Throttle (Idle) Switch
This switch is integral with the idle speed actuator (ISA)
motor. The switch provides a voltage signal to the ECU, which
increases or decreases the throttle stop angle in response to engine
operating conditions.
Transmission Gear Position Indicator
The gear position indicator is mounted on vehicles equipped
with automatic transaxles. It provides a signal to the ECU to
indicate that the transaxle is in a driving mode and not in Park or
Neutral.
Power Steering Pressure Switch
The switch increases the idle speed during periods of high
power steering pump load and low engine RPM.
A/C Switch
The A/C switch sends a signal to the ECU when the air
conditioner is operating and when the compressor clutch must be
engaged to lower the temperature. The ECU, in turn, increases engine
speed to compensate for the added load of the air conditioner.
FUEL CONTROL

RVB Rear Vacuum Break 

RWAL Rear Wheel Anti-Lock Brake 

RWD Rear Wheel Drive 

Recirc. Recirculate or Recirculation 

Reg. Regulator 

Rly. Relay 











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\









\









\









\





\f

"S" ABBREVIATION TABLE
"S" ABBREVIATION TABLE







\









\








\









\









\









\









\






 
ABBREVIATION DEFINITION 










\








\b
\









\









\









\









\









\






SAW Spark Angle Word 

SBC Single Bed Converter 

SBEC Single Board Engine Controller 

SC Super Charged 

SCC Spark Control Computer 

SCS Air Suction Control Solenoid 

SDM Supplemental Restraint System Diagnostic Module 

SDU SRS Diagnostic Unit 

SEN Sensor 

SES Service Engine Soon 

SFI Sequential (Port) Fuel Injection 

SIG RTN Signal Return circuit 

SIL Shift Indicator Light 

SIR Supplemental Inflatable Restraint 

SMEC Single Module Engine Controller 

SOHC Single Overhead Cam 

SOL or Sol. Solenoid 

SPFI Sequential Port Fuel Injection 

SPK Spark Control 

SPOUT Spark Output Signal 

SRS Supplemental Restraint System (Air Bag) 

SS 3/4-4/3 Shift Solenoid circuit 

SSI Solid State Ignition 

STAR Self-Test Automatic Readout 

STI Self Test Input circuit 

STO Self-Test Output 

SUB-O2 Sub Oxygen Sensor 

Sen. or Sens. Sensor 

Sol. Solenoid 

Sprchg. Supercharger 

Strg. Steering 

Susp. Suspension 

Sw. Switch 

Sys. System 











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\









\









\









\









\









\





\f

"T" ABBREVIATION TABLE
"T" ABBREVIATION TABLE







\









\








\









\









\









\









\








ABBREVIATION DEFINITION 










\








\b
\









\









\









\









\









\






T.V. Throttle Valve 

TAB Thermactor Air By-Pass 

TAC Thermostatic Air Cleaner 

TAD Thermactor Air Diverter 

TAN Tan 

TBI Throttle Body Injection 

are continually republished. In addition to these, standards for Drive
Train and Transmissions have recently been promulgated. Participating
shops utilize these Uniform Inspection & Communication Standards as
part of the inspection process and for communicating their findings to
their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not
satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method
has been incorporated which includes the "mystery shopping" of
outlets.
We welcome you to join us as we continue our outreach... with
your support, both the automotive repair industry and your customers
will reap the benefits. Please visit MAP at our Internet site www.
motorist.org or contact us at:
1444 I Street, NW Suite 700
Washington, DC 20005
Phone (202) 712-9042 Fax (202) 216-9646
January 1999
MAP UNIFORM INSPECTION GENERAL GUIDELINES
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
It is MAP policy that all exhaust, brake, steering,
suspension, wheel alignment, drive-line, engine performance and
maintenance, and heating, ventilation and air conditioning, and
electrical services be offered and performed under the standards and
procedures specified in these sections.
Before any service is performed on a vehicle, an inspection
of the appropriate system must be performed. The results of this
inspection must be explained to the customer and documented on an
inspection form. The condition of the vehicle and its components will
indicate what services/part replacements may be "Required" or
"Suggested". In addition, suggestions may be made to satisfy the
requests expressed by the customer.
When a component is suggested or required to be repaired or
replaced, the decision to repair or replace must be made in the
customer's best interest, and at his or her choice given the options
available.
This section lists the various parts and conditions that
indicate a required or suggested service or part replacement.
Although this list is extensive, it is not fully inclusive. In
addition to this list, a technician may make a suggestion. However,
any suggestions must be based on substantial and informed experience,

SHOE HARDWARE
SHOES
SOCKETS
SPEED SENSORS (ELECTRONIC WHEEL AND VEHICLE)
STEEL BRAKE LINES
STOPLIGHT SWITCHES
SWITCHES
TIRES
TOOTHED RINGS (TONE WHEEL)
VACUUM BOOSTERS
VACUUM HOSES
VALVES
WHEEL ATTACHING HARDWARE
WHEEL BEARINGS, RACES AND SEALS
WHEEL CYLINDERS
WIRING HARNESSES
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt:\
1) a Pledge of Assurance to their Customers and
2) the Motorist Assurance Program Standards of Service.
All participating service providers have agreed to subscribe
to this Pledge and to adhere to the promulgated Standards of Service
demonstrating to their customers that they are serious about customer
satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards
are continually re-published. In addition to these, standards for
Drive Train and Transmissions have recently been promulgated.
Participating shops utilize these Uniform Inspection & Communication
Standards as part of the inspection process and for communicating
their findings to their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not

satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method
has been incorporated which includes the "mystery shopping" of
outlets.
We welcome you to join us as we continue our outreach with
your support, both the automotive repair industry and your customers
will reap the benefits. Please visit MAP at our Internet site www.
motorist.org or contact us at:
1444 I Street, NW Suite 700
Washington, DC 20005
Phone (202) 712-9042 Fax (202) 216-9646
January 1999
MAP UNIFORM INSPECTION GENERAL GUIDELINES
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
It is MAP policy that all exhaust, brake, steering,
suspension, wheel alignment, drive-line, engine performance and
maintenance, and heating, ventilation and air conditioning, and
electrical services be offered and performed under the standards and
procedures specified in these sections.
Before any service is performed on a vehicle, an inspection
of the appropriate system must be performed. The results of this
inspection must be explained to the customer and documented on an
inspection form. The condition of the vehicle and its components will
indicate what services/part replacements may be "Required" or
"Suggested". In addition, suggestions may be made to satisfy the
requests expressed by the customer.
When a component is suggested or required to be repaired or
replaced, the decision to repair or replace must be made in the
customer's best interest, and at his or her choice given the options
available.
This section lists the various parts and conditions that
indicate a required or suggested service or part replacement.
Although this list is extensive, it is not fully inclusive. In
addition to this list, a technician may make a suggestion. However,
any suggestions must be based on substantial and informed experience,
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.

1) Adjust rear brakes. Check cable for binds, kinks or frayed
condition. Replace cable (if necessary). Release parking brake. Loosen\
lock nuts at parking brake cable equalizer under vehicle.
2) Tighten cables until wheels drag slightly when rotated by
hand. Loosen equalizer until wheels rotate freely and no drag is felt.
Tighten lock nuts and check operation of parking brake.
ROTOR SERVICING
RUNOUT
1) Measure rotor lateral runout by mounting a dial indicator
on support stand or steering spindle. Position indicator stylus so it
contacts center of rotor braking surface.
2) Zero indicator and turn rotor one revolution. Note
indicator reading. Runout must not exceed specification. See DISC
BRAKE ROTOR SPECIFICATIONS table. Refinish or replace rotor (if
necessary).
NOTE: Thickness of machined rotor must not be below minimum
thickness specification.
PARALLELISM
Measure rotor parallelism with a micrometer. Measure
thickness at 4 or more equally spaced points around rotor at
approximately 1" from edge of rotor. Variation must not exceed
specification. See DISC BRAKE ROTOR SPECIFICATIONS table. Refinish or
replace rotor (if necessary).
BRAKE SYSTEM BLEEDING
Hydraulic system bleeding is necessary any time air has been
introduced into system. Bleed brakes at all 4 wheels if master
cylinder lines have been disconnected or master cylinder has run dry.
Bleed brakes with vacuum bleeding equipment, pressure bleeding
equipment or by manually pumping brake pedal while using bleeder
tubes. Always bleed brake lines in sequence. See BLEEDING SEQUENCE
table.
MASTER CYLINDER BLEEDING
Bench Bleeding
1) Master cylinder must be bled before installation to
prevent excessive amounts of air from entering the brake system,
creating poor brake operation.
2) Place master cylinder in soft-jawed vise. DO NOT tighten
vise enough to damage master cylinder. Install bleeder tubes in both
outlets of master cylinder. See Fig. 5.

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

\003
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








\









\









\









\









\





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.









\









\









\









\









\





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.

1) Coat intermediate shaft with lubricant and carefully slide
through seal and engage in drive axle splines. Install retaining clip.
2) Install shift collar on axle shaft. Install outer axle
shaft and check for smooth operation of shift collar.
3) Apply bead of silicone sealer to inspection cover and
install cover. Fill axle housing with 2.5 pts. (1.2L) of 75W 90 gear
oil. Pour a small amount of gear oil on shift collar and install
disconnect housing. Ensure shifting fork is properly positioned in
shift collar.
4) To complete installation, reverse removal procedure.
Tighten all bolts and nuts to specification. See TORQUE SPECIFICATIONS
table at end of this article.
FRONT AXLE ASSEMBLY R & I
REMOVAL (CHEROKEE, COMANCHE, WAGONEER)
1) Raise and support vehicle. Remove tire and wheel assembly.
Remove hubs, spindles and axles. See FRONT HUB, BEARING, SPINDLE &
AXLE SHAFT in this article.
2) Disconnect vacuum hoses and electrical connections from
shift motor. Disconnect stabilizer bar, track bar and steering damper.
3) Disconnect drive shaft at pinion yoke and tie to frame.
Remove left and right tie rod ends from knuckles.
4) Support axle assembly on floor jack. Remove lower shock
mounts. Disconnect axle housing-to-frame control arms at axle. Lower
floor jack slowly and remove axle assembly. Remove coil spring lower
bracket and coil spring.
INSTALLATION
1) Place axle housing on floor jack and position under
vehicle. Install coil springs and raise assembly into position. Ensure
top of coil springs seat in spring pocket.
2) Check all bushings and mounting hardware for wear or
damage. To complete installation, reverse removal procedure. Tighten
all bolts and nuts to specification. See TORQUE SPECIFICATIONS table
at end of this article. Fill axle assembly with gear oil. Check wheel
alignment.
REAR HUB, BEARINGS & AXLE SHAFTS R & I
1) Raise and support vehicle. Remove tire and wheel assembly.
Remove axle flange nuts or bolts. If nuts are used, rap center of axle
flange sharply with hammer to loosen tapered dowels. Remove bolts or
dowels and pull axle shaft out of hub.
2) Depending on application, bend back ears of lock washer,
or remove locking wedge from nut, or remove snap ring and key. Remove
bearing adjusting nut(s) and remove hub assembly.
3) Remove inner hub seal and bearing. Inspect bearings and
races for wear. To replace bearing, drive outer race from bearing hub
using a punch and hammer. Install new race being careful not to chip
or dent race. Ensure new race is seated in hub.
4) Pack bearings with multi-purpose grease. Install new seal.
Carefully install hub on axle spindle to avoid damaging seal lip and
spindle threads.
5) Install outer bearing and adjusting nut. Tighten bearing
adjusting nut in steps. See REAR HUB BEARING ADJUSTING SPECIFICATIONS
table. Install lock ring if used. Install spindle lock nut if used and
tighten to proper specification. See REAR HUB BEARING ADJUSTING
SPECIFICATIONS table.

VEHICLE SPEED SENSORS
VENTS
VIBRATION DAMPERS
WHEEL ATTACHMENT HARDWARE
WHEEL SPEED SENSORS
WIRING HARNESSES AND CONNECTORS
YOKES AND SLIP YOKES
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
(1) a Pledge of Assurance to their Customers and (2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection were recently published.
Further, revisions to all of these inspection communication standards
are continually republished. In addition to these, standards for Drive
Train and Transmissions have recently been promulgated. Participating
shops utilize these Uniform Inspection & Communication Standards as
part of the inspection process and for communicating their findings to
their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not
satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method