1988 JEEP CHEROKEE tire size

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AN TI- L O CK B RAK E S A FE TY P R EC AU TIO NS

1988 J e ep C hero ke e
GENERAL INFORMATION
Anti-Lock Brake Safety Precautions
* PLEASE READ THIS FIRST *
This article is intended for general information purposes
only. This information may not apply to all makes and models. If
vehicle is equipped with Anti-Lock Brake System (ABS), refer to
appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES section for
description, operation, depressurizing, testing, system bleeding,
trouble shooting and servicing of specific system.
WARNING: Failure to depressurize ABS could lead to physical injury.
ANTI-LOCK BRAKE SAFETY PRECAUTIONS
WARNING: Failure to depressurize ABS could lead to physical injury.
* NEVER open a bleeder valve or loosen a hydraulic line
while ABS is pressurized.
* NEVER disconnect or reconnect any electrical connectors
while ignition is on. Damage to ABS control unit may result.
* DO NOT attempt to bleed hyudarulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES section.
* Only use specially designed brake hoses/lines on ABS equipped
vehicles.
* DO NOT tap on speed sensor components (sensor, sensor rings).
Sensor rings must be pressed into hubs, NOT hammered into
hubs. Striking these components can cause demagnetization or
a loss of polarization, affecting the accuracy of the speed
signal returning to the ABS control unit.
* DO NOT mix tire sizes. Increasing the width, as long as tires
remain close to the original diameter, is acceptable. Rolling
diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* DO NOT contaminate speed sensor components with grease. Only
use recommended coating, when system calls for an
anti-corrosion coating.
* When speed sensor components have been removed, ALWAYS check
sensor-to-ring air gaps when applicable. These specifications
can be found in each appropriate article.
* ONLY use rocommended brake fluids. DO NOT use silicone brake
fluids in an ABS equipped vehicle.
* When instlling transmittion devices (CB's, telephones, etc.)
on ABS equipped vehicles, DO NOT locate the antenna near the
ABS control unit (or any control unit).
* Disconnect all on-board computers, when using electric
welding equipment.
* DO NOT expose the ABS control unit to prolonged periods of
high heat (185
F/85C for 2 hours is generally considered a
maximum limit).

in the brake fluid.
4) Using proper sized rod, apply and release master cylinder
until no air bubbles exist in brake fluid flow. Once all air bubbles
are gone from master cylinder secure cap and install.
5) Bleeder tubes should be left installed on master cylinder
until master cylinder in installed. Master cylinder must be bled at
brake lines and wheels after installation.
Bleeding On Vehicle
1) Install master cylinder on vehicle after bench bleeding.
Remove bleeder lines and install brake lines. DO NOT fully tighten
brake lines at this time.
2) Slowly force brake pedal to the floor and hold in this
position. Tighten brake lines and release brake pedal. Repeat
procedure until no air bubbles exist at brake lines. Remaining wheel
cylinder or calipers may be require bleeding.
HYDRAULIC CONTROL VALVES
Hold Off Valve
1) Prior to the pressure tank bleeding procedure, the hold
off valve incorporated in the combination valve must be correctly
positioned. This allows brake fluid to flow through the combination
valve to the entire brake system.
2) The valve stem of the hold off valve may be retained using
tools available from Chrysler Motors (C-4121) or General Motors
(J-23709) during bleeding procedure. See Figs. 2 and 3. Remove valve
retainer once brake bleeding procedure is complete.
CAUTION: DO NOT use rigid clamp to position valve stem. Damage to
the valve assembly may result causing brake failure.
Fig. 2: Positioning Hold Off Valve
Courtesy of American Motors/Jeep Corp.

Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Binding, affecting
performance ............ A .. Require repair or replacement.
Binding, not affecting
performance ............ 2 .. Suggest repair or replacement.
Broken .................. A .. Require repair or replacement.
Burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Burned, not affecting
performance ............ 2 ........... ( 1) Suggest repair or
replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Float saturated ......... A ............ Require replacement.
Leaking ................. A .. Require repair or replacement.
Malfunctioning .......... A ........... ( 2) Require repair or
replacement.
Melted, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Melted, not affecting
performance ............ 2 ........... ( 1) Suggest repair or
replacement.
Missing ................. C ............ Require replacement.
Out of adjustment ....... B .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Won't return ............ A .. Require repair or replacement.
Worn .................... 1 ............ Suggest replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Includes inoperative, intermittent operation, or failure to
perform all functions.









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TIRES
Consult the vehicle owner's manual or vehicle placard for
correct size, speed ratings, and inflation pressure of the original
tires.
TIRE INSPECTION

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Condition Code Procedure
Tire diameter incorrect,
affecting ABS or TCS ... A ............ Require replacement.
Tire pressure incorrect,
affecting ABS or TCS ... A .. Require repair or replacement.
Tire size incorrect,
affecting ABS or TCS ... A ............ Require replacement.









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TOOTHED RINGS (TONE WHEEL)
NOTE: Copied from Drivetrain UIGs.
If the toothed ring requires replacement and cannot be
replaced as a separate component, replace the assembly of which the
ring is a part.
TOOTHED RING INSPECTION









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Condition Code Procedure
Alignment incorrect ..... B ............... Require repair or
replacement.
Bent .................... B ............ Require replacement.
Contaminated, affecting
performance ............. A ........ Require repair. Identify
and correct cause.
Cracked ................. B ............ Require replacement.
Loose ................... A ............. Require replacement
of worn parts.
Missing ................. C ............ Require replacement.
Number of teeth
incorrect .............. B ............ Require replacement.
Teeth broken ............ A ............ Require replacement.
Teeth damaged, affecting
performance ............ A ............ Require replacement.









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VACUUM BOOSTERS
VACUUM BOOSTER INSPECTION








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Condition Code Procedure
Applies too much assist
(oversensitive) ........ A ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Auxiliary vacuum pump
inoperative ............ A ........... ( 1) Require repair or
replacement.
Check valve grommet
deteriorated, affecting
performance ............ A .. Require replacement of grommet.

Fig. 5: Bleeding Master Cylinder
Courtesy of American Motors/Jeep Corp.
3) Fill master cylinder with clean brake fluid that meets DOT
3 specifications. Ensure that the end of bleeder tubes are submerged
in the brake fluid.
4) Using proper sized rod, apply and release master cylinder
until no air bubbles exist in brake fluid flow. Once all air bubbles
are gone from master cylinder secure cap and install.
5) Bleeder tubes should be left installed on master cylinder
until master cylinder in installed. Master cylinder must be bled at
brake lines and wheels after installation.
Bleeding On Vehicle
1) Install master cylinder on vehicle after bench bleeding.
Remove bleeder lines and install brake lines. DO NOT fully tighten
brake lines at this time.
2) Slowly force brake pedal to the floor and hold in this
position. Tighten brake lines and release brake pedal. Repeat
procedure until no air bubbles exist at brake lines. Remaining wheel
cylinder or calipers may be require bleeding.
HYDRAULIC CONTROL VALVES
Hold Off Valve
1) Prior to the pressure tank bleeding procedure, the hold
off valve incorporated in the combination valve must be correctly
positioned. This allows brake fluid to flow through the combination
valve to the entire brake system.
2) The valve stem of the hold off valve may be retained using

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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.

Vibration can come from many sources. Before overhauling
driveline, check other sources of possible vibration as follows:
* Tires and wheels - Check tire inflation and wheel balance.
Check for foreign objects in tread, damaged tread, mismatched
tread patterns or incorrect tire size.
* Center Bearing - Tighten drive shaft center bearing
mounting bolts. If bearing insulator is deteriorated or
oil-soaked, replace it.
* Engine & Transmission Mountings - Tighten mounting bolts.
If mountings are deteriorated, replace them.
* Drive Shaft - Check drive shaft for damage or dents that
could affect balance. Check for undercoating adhering to
shafts. If present, clean shafts thoroughly.
* Universal Joints - Check for foreign material stuck in
joints. Check for loose bolts and worn bearings.
ADJUSTMENTS
DRIVE SHAFT PHASING
One-Piece Shafts
Check that flanges on either end of drive shaft are in same
plane. Often there are arrows on slip joint and drive shaft to aid in
alignment. See Fig. 2. If flanges are not in same plane, disassemble
universal joint and align.
Fig. 2: Slip Joint Alignment Arrows
Align arrows for proper shaft phasing.
2-Piece Shafts
1) All General Motors models with 32 splines use keys on
spline and slip joint, which can only mate in correct position. On
most models with 2-piece shafts, proper phasing is accomplished by
keys on spline and slip joint.

Fig. 6: Measuring Valve Stem-to-Guide Clearance - Typical
This Graphic For General Information Only
Lower valve approximately 1/16" below valve seat. Push valve
stem against valve guide as far as possible. Adjust dial indicator to
zero. Push valve stem in opposite direction and note reading.
Clearance must be within specification.
If valve guide clearance exceeds specification, valves with
oversize stems may be used or valve guide must be replaced. On some
applications, a false guide is installed, then reamed to proper
specification. Valve guide reamer set is used to ream valve guide to
obtain proper clearance for new valve.
Reaming Valve Guide
Select proper reamer for valve stem. Reamer must be of
proper length to provide clean cut through entire length of valve
guide. Install reamer in valve guide and rotate to cut valve guide.
See Fig. 7 .