differential JEEP CHEROKEE 1988 Service Repair Manual

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* B RAK E S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *

1 988 J e ep C hero ke e
GENERAL INFORMATION
Brake Systems - Motorist Assurance Program
Standards For Automotive Repair
All Makes & Models
CONTENTS
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
ACCELEROMETERS (G SENSOR OR LATERAL)
ACCUMULATORS
ANCHOR PINS
ANTI-LOCK BRAKE SYSTEMS
BACKING PLATES
BRAKE FLUID
BRAKE FRICTION MATERIAL
BRAKE PADS
BRAKE PEDALS
BRAKE SHOES
BRAKE SHOE HARDWARE
BRAKE STOPLIGHT SWITCHES
BULB SOCKETS
BULBS AND LEDS
CALIPER HARDWARE
CALIPERS
CONTROLLERS
DIGITAL RATIO AXLE CONTROLLERS AND BUFFERS (DRAC AND DRAB)
DISABLE SWITCHES
DRUMS
ELECTRICAL PUMPS AND MOTORS
ELECTRONIC CONTROLLERS
FLUID
FLUID LEVEL SENSOR SWITCHES
FOUR WHEEL DRIVE SWITCHES
FRICTION MATERIAL
G SENSORS
HOSES
HYDRAULIC MODULATORS
HYDRO-BOOSTERS
HYDRO-ELECTRIC BOOSTERS (POWERMASTER)
IGNITION DISABLE SWITCHES
LATERAL ACCELERATION SWITCHES
LEDS
LENSES
MASTER CYLINDERS
MODULATORS
MOTORS
PARKING BRAKE SWITCHES
PARKING BRAKE SYSTEMS
PADS
PEDAL TRAVEL SWITCHES
PEDALS
POWERMASTER
PUMPS
PRESSURE DIFFERENTIAL SWITCHES
PRESSURE SWITCHES
RELAYS
ROTORS
SELF-ADJUSTING SYSTEMS

missing ................ C .. Require replacement of missing
parts.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
(1) - Inoperative includes intermittent operation.









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PADS
See FRICTION MATERIAL .
PEDAL TRAVEL SWITCHES
See SWITCHES.
PEDALS
See BRAKE PEDALS.
POWERMASTER
See HYDRO-BOOSTERS .
PUMPS
See ELECTRICAL PUMPS AND MOTORS .
PRESSURE DIFFERENTIAL SWITCHES
See SWITCHES.
PRESSURE SWITCHES
See SWITCHES.
RELAYS
NOTE: Copied from Electrical UIGs
RELAY INSPECTION









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Condition Code Procedure
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.
Housing broken .......... A ............ Require replacement.
Housing cracked ......... 2 ............ Suggest replacement.
Inoperative ( 1) ......... A ............ Require replacement.
Missing ................. C ............ Require replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned,
affecting performance .. A ........... ( 2) Require repair or
replacement.

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DIF FE R EN TIA L - D AN A T R AC -L O K & P O W ER -L O K

1988 J e ep C hero ke e
1988 Positive Traction Differentials - Dana Power-Lok &
Trac-Lok
Jeep
DESCRIPTION
The limited slip differential uses 2 sets of multiple disc
clutches to control differential action. Dana produces 2 types of
positive traction differentials. The Power-Lok 4-pinion differential
is a split-case type. The Trac-Loc 2-pinion differential is a single-
case type.
OPERATION
When one or both wheels are on a low-traction surface such as
snow, ice or mud, the friction between the clutch plates will transfer
a portion of the usable torque to the wheel with the most traction.
The wheel on ice or snow will have a tendency to operate with the
opposite wheel in a combined driving effort.
AXLE RATIO & IDENTIFICATION
To determine axle ratio, see DRIVE AXLE RATIO IDENTIFICATION
in this section.
LUBRICATION
NOTE: Always use special positive traction differential lubricant
as specified by manufacturer.
DIAGNOSIS & TESTING
DANA 2-PINION TRAC-LOK
1) Drive vehicle to thoroughly warm up lubricant in rear
axle. Place a piece of slick paper over a smooth formica board. Ensure
formica board is on flat and level floor.
Fig. 1: Exploded View of Jeep Single-Case Dana Trac-Lok Differential

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

Plate (J 23781-7) in bottom side gear. Install grease in centering
hole of step plate. Position Rotating Tool (J 23781-3) on step plate
tool. Coat threads of Forcing Screw (J 8646-2) with oil.
2) Insert forcing Screw (J 8646-2) through case and thread
into rotating tool. Thread screw through tool until it contacts
centering hole in step plate. Tighten forcing screw to relieve clutch
pack tension from pinions. Remove pinion thrust washers.
3) Tighten forcing screw until all clutch pack tension is
relieved from pinions. Slide rotating tool pawl so it engages with
side gear teeth. Rotate side gears with rotating tool until pinions
can be removed through case opening.
4) Remove forcing screw, rotating tool, upper side gear and
clutch pack. Remove differential case from axle shaft. Remove
remaining side gear, clutch pack and step plate tool. Remove retainer
clips from clutch packs. Mark clutch packs for reassembly reference.
Using a press, remove differential bearings.
Cleaning & Inspection
Clean all parts and dry with compressed air. If any clutch
plates or discs require replacement, all plates and discs should be
replaced. Replace any worn or damaged components.
NOTE: For adjustment procedures, see DANA SEMI-FLOATING or
FULL FLOATING AXLE articles in this section
Reassembly
1) Lightly lubricate clutch pack discs with axle lubricant.
Assemble clutch pack discs and install retaining clips on ears of
discs. See Fig. 3. Install assembled clutch packs on side gears.
Fig. 3: Typical Clutch Pack Assembly
2) Mount differential case on axle shaft. Install first
clutch pack and side gear in bottom bore of case. Ensure retaining
clips remain seated in case pockets. Install Step Plate (J 8646-2) in

clutch pack just installed.
3) Install remaining side gear and clutch pack in case. Hold
assembly in position and install rotating tool and forcing screw.
Tighten forcing screw and compress clutch packs. Install pinions.
Rotate side gear with tool pawl until each pinion is aligned with
pinion shaft bore.
4) Install pinion thrust washers and pinion shaft. Install
pinion thrust washers and pinion shaft. Install snap rings on pinion
shaft. Remove differential from axle shaft. Remove shaft from vise.
Using Remover (J 22912-01), remove differential bearings. Install end
play shims on each side of case. Reinstall differential bearings.
5) Position ring gear on differential case. Install NEW ring
gear bolts and tighten to 52 ft. lbs. (70 N.m).
DANA 4-PINION POWER-LOK
NOTE: Differential bearings do not need to be removed to overhaul.
Disassembly
1) Mark case halves, pinion mate shafts and ramps for
reassembly reference. Clamp differential assembly in soft-jawed vise
and loosen case half bolts ( DO NOT remove bolts). Position
differential assembly on bench with ring half of case down. Remove
case attaching bolts. Remove cover half of case.
2) Remove pinion mate gear, side gear ring and clutch pack.
Keep parts together for reassembly reference. Remove parts from drive
gear half of case.
Cleaning & Inspection
Clean all parts and dry with compressed air. If any clutch
plates or discs require replacement, it is recommended that all plates
and discs be replaced. Replace any part that is worn or damaged.
Reassembly
NOTE: For adjustment procedures, see DANA SEMI-FLOATING or
FULL FLOATING AXLE articles in this section.
1) Position side gear ring from drive gear half of case on a
pinion flange. Coat clutch plates with Hypoid Gear Lubricant (C6A-Z-
19580-E). Reassemble parts in correct order. See Fig. 1. Install ring
gear half of case over clutch pack and side gear ring. Ensure clutch
plate lugs enter slots in case and case bottoms on clutch pack.
2) Hold assembly together and turn case half upside down.
Install gear in side gear ring. Install mate shaft and pinions on side
gear ring. Align mate shaft and case markings. Install cover half mate
shaft and pinions. Align markings.
3) Install side gear on pinions. Position side gear ring on
side gear and pinions. Assemble clutch pack on side gear. See Fig. 4.
Align clutch plate lugs and install all parts in case. Position cover
half of case over assembly. Align case marks made during disassembly.
4) Lubricate bolt threads with axle lube and install case
bolts. Using both axle shafts, align splines of side gear and side
gear ring. Tighten case bolts to 65-70 ft. lbs. (89-94 N.m).
5) Remove axle shafts. If properly assembled, each pinion
mate cross shaft should be tight on its ramp. If clearance is present,
it should not exceed .010" (.254 mm).

Fig. 4: Power-Lok Differential Clutch Pack Assembly
Courtesy of Ford Motor Co.

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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.

REMOVAL
1) Raise and support vehicle. Remove wheels, hubs and axles.
See REAR HUB, BEARINGS AND AXLE SHAFTS.
2) Remove lower shock mounts and stabilizer bar mount.
Disconnect drive shaft and tie up. Remove hydraulic brake line at
junction and plug.
3) Disconnect park brake cables and hydraulic brake lines to
wheel cylinders or calipers. Remove brake backing plate or caliper.
4) Support axle housing with floor jack and remove leaf
spring "U" bolts. Carefully lower axle housing and remove from
vehicle.
INSTALLATION
Place axle housing on floor jack. Raise axle and install "U"
bolts and nuts. To complete installation, reverse removal procedure.
Tighten all bolts and nuts to specification. See TORQUE SPECIFICATIONS
table at the end of this article and REAR HUB BEARING ADJUSTING
SPECIFICATIONS table.
PINION SEAL & YOKE R & I
REMOVAL
1) Raise and support vehicle. Mark drive shaft-to-yoke
contact area for reassembly reference. Remove drive shaft-to-yoke
attaching nuts/strap bolts. Discard used strap bolts. Remove drive
shaft.
2) Using a breaker bar and Pinion Nut Remover (8614-01),
remove pinion nut and washer. See Fig. 3. Using Yoke Pullers (8614-
01), (8614-02) and (8614-03), remove yoke. See Fig. 4. Using Pinion
Seal Remover (J-9233 or J-7583), remove pinion seal from front
differential housing. See Fig. 5.
Fig. 3: Removing Pinion Nut & Washer

Fig. 5: Removing Pinion Seal
INSTALLATION
Using Seal Installer (J22661), drive new seal into front
differential housing. See Fig. 6. Tighten yoke attaching nut to 210
ft. lbs. (285 N.m). Using NEW strap bolts, align and install drive
shaft. Tighten strap bolts to 14 ft. lbs. (19 N.m). Fill differential
with SAE 75W-90 gear lubricant.