differential JEEP CHEROKEE 1988 Service Owner's Manual

perform overhaul.
1) Raise and support rear of vehicle. Remove rear cover and
drain lubricant. Remove wheels, brake drums, hubs and axle shafts.
2) Mark differential bearing caps for reassembly reference
and loosen them until a few threads remain engaged. Pry differential
loose and remove bearing caps and differential from housing.
3) Mark bearing caps, races and shims for reassembly
reference. Remove differential side bearings with a puller. Remove
differential and ring gear from case. Remove pinion shaft lock pin.
4) Using 2 feeler gauges, measure differential side gear
clearance. Insert an equal distance feeler gauge between each side
gear and case. Continue checking clearance until each feeler gauge is
a tight drag fit. Ensure side clearance does not exceed .007" (.18 mm)\
on either side. If side gear clearance exceeds specification, replace
side gear thrust washers.
5) Remove pinion yoke and nut. Retain pinion nut for pinion
depth adjustment during reassembly. Tap pinion gear end with a soft
faced mallet to release it from front bearing. Remove pinion gear,
pinion bearings and preload collapsible spacer. Discard collapsible
spacer.
6) Remove pinion seal and pinion rear bearing cup. Remove and
retain pinion depth shim located under rear bearing cup. Remove pinion
front bearing cup. Using a press, remove pinion gear rear bearing.
CLEANING & INSPECTION
Clean all components in solvent and dry with compressed air.
Inspect all components for excessive wear or damage and replace as
necessary.
REASSEMBLY
NOTE: Ensure correct shims have been chosen to obtain proper
ring gear backlash and bearing preload before reassembly.
See ADJUSTMENTS in this article.
Drive Pinion
1) Press rear bearing on pinion stem with large diameter of
roller cage toward gear. Clean housing bearing bores. Place shim in
rear bearing bore and install rear bearing cup.
NOTE: When installing a new gear set, use original depth shim as a
starting point. Chamfered side of shim must be installed to
bottom side of rear bearing cup bore.
2) Install front bearing cup into housing. Install drive
pinion through rear bearing cup. Install front bearing, yoke and
original pinion nut. Tighten nut to remove bearing end play only.
NOTE: A new nut and collapsible spacer are not installed at this
time, as pinion will be removed after a depth measurement.
Differential Case
1) Assemble side gears and thrust washers and install into
differential case. Ensure side gear thrust washers were replaced in
clearance measured at disassembly was greater than .007" (.18 mm).
2) Install differential pinions and thrust washers in case.
Ensure pinions are aligned with shaft bores. Recheck side gear
clearance. If clearance exceeds .007" (.18 mm), side gears must be
replaced.
3) Install differential pinion shaft and lockpin. Using
Remover (J-22912-01), remove differential bearings. Install correct

size end play shims on each side of differential case. Position and
install ring gear on differential case. Install replacement ring gear
bolts and tighten standard axle ring gear bolts to 70-90 ft. lbs.
(95-122 N.m). Tighten heavy duty drive axle bolts to 105 ft. lbs.
(142 N.m).
4) Check ring gear backlash. See RING GEAR BACKLASH in
ADJUSTMENTS. Lightly lubricate differential bearings, cups, gears and
thrust washers with axle lubricant. Install bearing cups on
differential bearings. Install differential in axle housing.
5) Using a soft faced hammer, tap outer edges of differential
bearing cups to seat them in housing. Install differential bearings
caps and tighten cap bolts to 57 ft. lbs. (77 N.m).
6) Recheck and verify ring gear backlash has not changed.
Install axle housing cover. Tighten cover bolts to 14 ft. lbs. (19 N.
m). Refill axle with 75-90W gear lubricant.
ADJUSTMENTS
DRIVE PINION DEPTH
1) Check numbers painted on drive pinion and ring gear. First
number on pinion must match number on ring gear. Second number on
pinion is pinion depth variance. If number is preceded by a plus sign,
add that number to standard pinion depth. If number is preceded by a
minus sign, subtract that amount from standard pinion depth. This will
give desired pinion depth. Record this measurement for future
reference.
2) If numbers painted on drive gear and ring gear do not
match, gears are not a matched set and should not be used. Some
factory installed sets may have .01" (.25 mm) or .02" (.50 mm)
machined off pinion end face.
3) Identifying numbers will appear as "+23". Number "2"
indicates .02" (.50 mm) was removed from end face and number "3" is
pinion depth variance. If marked "+16", number "1" indicates .010"
(.25 mm) was removed from end face and number "6" is pinion depth
variance.
4) Standard pinion depth on standard drive axle is 2.095"
(53.21 mm). Standard pinion depth on heavy duty drive axle is 2.547"
(64.69 mm).
Fig. 3: Pinion Depth & Preload Shim Location
5) Measure thickness of original pinion depth shim. Note
pinion depth variance numbers marked on old and new pinion gears.
Refer to PINION DEPTH SHIM ADJUSTMENT SPECIFICATIONS at end of this

article and determine amount to be added or subtracted from original
shim thickness to obtain starter shim thickness. DO NOT use starter
shim thickness as a final shim setting.
6) Install rear bearing on pinion gear. On heavy duty rear
axle, large end of bearing faces gear end of pinion. Press bearing
against rear face of gear.
7) On all axles, clean pinion bearing bores in axle housing
to ensure accurate measurement. Install and center starter shim in
housing bearing cup bore. If shim is chamfered, ensure chamfered side
faces bottom of bearing cup bore.
8) Install pinion rear and front bearing cups. Install pinion
gear in rear bearing cup and install pinion front bearing and yoke on
pinion gear. DO NOT install oil seal or collapsible spacer at this
time. Install and tighten original pinion nut only enough to remove
end play. Determine depth variance marked on pinion gear.
9) Install Arbor (J-5223-4) and Discs (J-5223-23) in
differential bearing cup bores. Ensure discs are fully seated in
bearing cup bores. Install bearing caps over discs and install bearing
cap bolts. Tighten bolts, but not to specified torque.
10) Position Gauge Block (J-5223-20) against end of drive
pinion with Clamp (J-5223-24) and Bolt (J-5223-29). See Fig. 4. Extend
clamp bolt until it presses against gauge block enough to prevent
gauge block from moving.
11) Loosen thumbscrew in end of gauge block to allow plunger
to contact arbor. When plunger contacts arbor, tighten thumbscrew,
taking care not to disturb plunger position.
12) Remove gauge block and measure distance from end of anvil
to top of plunger head, using a 2-3" (51-76 mm) micrometer. Record
this measured pinion depth for future reference.
13) Remove gauging tools, drive pinion and rear bearing cup.
Remove drive pinion depth shim and record thickness. Add shim
thickness to measured pinion depth. From this total subtract desired
pinion depth. For an example, see DETERMINING CORRECT SHIM THICKNESS
table.
DETERMINING CORRECT SHIM THICKNESSES









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Application In. (mm)
Standard Drive Axle
Standard Pinion Depth .............................. 2.095 (53.21)\
Pinion Depth Variance ............................... - .004 (.10)\
Desired Pinion Depth .............................. =2.091 (53.11)\
Measured Pinion Depth .............................. 2.100 (53.34)\
Starting Shim Thickness ............................ + .096 (.096)\
Total Measured Thickness Depth .................... =2.196 (55.77)\
Total Measured Pinion Depth ........................ 2.196 (55.77)\
Desired Pinion Depth .............................. -2.091 (53.11)\
Correct Shim Thickness .............................. =.105 (2.66)\
Heavy Duty Drive Axle
Standard Pinion Depth .............................. 2.547 (64.69)\
Pinion Depth Variance ............................... + .007 (.18)\
Desired Pinion Depth .............................. =2.554 (64.87)\
Measured Pinion Depth .............................. 2.550 (64.77)\
Starting Shim Thickness ............................. +.098 (2.49)\
Total Measured Pinion Depth ....................... =2.648 (67.26)\
Total Measured Pinion Depth ........................ 2.648 (67.26)\
Desired Pinion Depth .............................. -2.554 (64.87)\
Correct Shim Thickness .............................. =.094 (2.39)\









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14) The result represents correct shim thickness to be
installed. Install correct thickness shim in rear bearing bore and

2) Slowly tighten pinion nut until torque required to rotate
pinion gear is 15-25 INCH lbs. (2-3 N.m). Check torque frequently and
only tighten nut in small amounts.
CAUTION: DO NOT overtighten pinion nut. If preload torque is
exceeded, collapsible spacer must be replaced and preload
reset.
DIFFERENTIAL BEARING END PLAY
1) Place bearing cup over each differential bearing. Install
differential case assembly (without drive gear) in axle housing. On
standard drive axles, install a .142" (3.60 mm) shim on each side of
differential bearing cup and housing. On heavy duty drive axles,
install a .080" (2.03 mm) shim on each side of differential bearing
cup and housing.
2) Install bearing caps and tighten bolts finger tight. Mount
dial indicator to housing so indicator button touches ring gear face
of differential case. Prying between shims and housing, move assembly
to one side. Zero dial indicator, then pry assembly to opposite side.
Read and record indicator reading. DO NOT zero or read indicator while
prying.
3) Amount read on indicator is shim thickness which must be
added in order to arrive at a no preload or end play condition. Shims
are available in thicknesses of .142" (3.60 mm) to .174" (4.41 mm) i\
n
.002" (.050 mm) increments.
4) When all side play is eliminated, check drive gear face of
case for runout. Runout should not exceed .002" (.050 mm). Remove case\
from housing and retain shims used to eliminate side play. See Fig. 5.
Fig. 5: Differential Bearing End Play & Runout Measurement
RING GEAR BACKLASH ADJUSTMENT
1) Install differential and ring gear assembly in housing

using shims selected to remove end play. Tighten bearing cap bolts
evenly to 57 ft. lbs. (77 N.m) for standard drive axle and 85 ft. lbs.\
(115 N.m) for heavy duty drive axle. Attach a dial indicator to
housing so button of indicator contacts drive side of a tooth of ring
gear, at a right angle to tooth. See Fig. 6. Rock ring gear and note
movement on dial indicator.
2) Backlash should be .005-.009" (.13-.23 mm) with .008"
(.20 mm) desired. To increase backlash, install thinner shim on ring
gear side of case and a thicker shim on opposite side of case. To
decrease backlash, reverse placement of shims. DO NOT change total
shim thickness, alter positions only.
DIFFERENTIAL BEARING PRELOAD
1) Differential bearings are preloaded by increasing existing
shim thickness by .004" (.10 mm). Install differential bearing shims
in axle housing bearing bore. DO NOT distort shims by hammering them
into housing.
2) Assemble bearing cups on bearings (cups should completely
cover rollers). Position differential so bearings just start to enter
in axle housing bearing bores. Keep assembly square in housing and
push in as far as possible.
3) Using a soft hammer, tap outer edge of bearing cups until
seated in housing. Install bearing caps, aligning marks made at
disassembly. Install and tighten bolts. Preloading differential
bearings may change backlash setting so recheck backlash and correct
as necessary.
Fig. 6: Checking Ring Gear Backlash
4) After all adjustments, check gear tooth pattern. See the
GEAR TOOTH CONTACT PATTERNS article in this section.

AXLE ASSEMBLY SPECIFICATIONS TABLE








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Application Specification
Axle Shaft End Play ........................ .004-.008" (.10-.20 mm)\
Differential Bearing Preload ........................ .008" (.20 mm)\
Differential Case Face Runout ....................... .002" (.05 mm)\
Differential Side Gear Case Clearance ........... 0-.007" (0-.18 mm)\
Oil Capacity
Standard Drive Axle .............................. 2.5 pts. (1.2L)\
Heavy Duty Drive Axle ............................. 4.7 pts (2.2L)\
Pinion Bearing Preload ................... 15-25 INCH lbs. (2.3 N.m)\
Pinion Gear Depth (Standard)
Standard Drive Axle ............................ 2.095" (53.21 mm)\
Heavy Duty Drive Axle ........................... 2.547" (64.7 mm)\
Ring Gear
Backlash ................................. .005-.009" (.13-.23 mm)\
Preferred ......................................... .008" (.20 mm)\









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TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE








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Application Ft. Lbs. (N.m)
Axle Housing Cover ......................................... 14 (19)\
Axle-to-Leaf Spring "U" Bolts .............................. 52 (70)\
Brake Support Plate Bolts .................................. 32 (43)\
Differential Bearing Bolts
Standard Drive Axle ...................................... 57 (77)\
Heavy Duty Drive Axle ................................... 85 (115)\
Rear Axle Filler Plug
Standard Drive Axle ...................................... 25 (34)\
Heavy Duty Drive Axle .................................... 15 (20)\
Rear Spring Front Bolt ................................... 111 (150)\
Rear Spring Rear Shackle Nuts ............................ 111 (150)\
Ring Gear Bolts
Standard Drive Axle ............................... 70-90 (95-122)\
Heavy Duty Drive Axle .................................. 105 (142)\
Shock Absorber-to-Axle Nut ................................. 44 (60)\
Universal Joint Clamp Strap Bolts .......................... 14 (19)\
Wheel Lug Nuts ............................................ 75 (102)\









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PINION DEPTH SHIM ADJUSTMENT SPECIFICATIONS
PINION DEPTH SHIM ADJUSTMENT CHART (INCHES)








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Old Pinion Marking Specification
+4
New Pinion Marking
-4 ....................................... +0.008
-3 ....................................... +0.007
-2 ....................................... +0.006
-1 ....................................... +0.005
0 ........................................ +0.004
+1 ....................................... +0.003
+2 ....................................... +0.002
+3 ....................................... +0.001
+4 ............................................ 0

2) On models with 2-piece shafts, rotate transmission yoke
until trunnion is in horizontal plane. Install front drive shaft with
"U" joint trunnion in vertical plane. Connect bearing support to
crossmember.
3) Ensure that front face of bearing support is perpendicular
(90 degrees) to centerline of drive shaft. Install rear drive shaft
with "U" joint trunnion of slip joint in vertical plane.
4) Set differential pinion yoke trunnion in vertical plane.
Connect rear drive shaft to pinion yoke. If 2-piece shaft is correctly
installed, centerline of trunnions at each end of individual shafts
will be parallel. See Fig. 3.
Fig. 3: Phase Alignment Of 2-Piece Drive Shafts
Trunnion yoke ears on each shaft must be parallel.
DRIVE SHAFT BALANCE TEST
1) Drive shaft imbalance may often be cured by disconnecting
shaft and rotating it 180 degrees in relation to other components.
Test by raising rear wheels off ground, and turning shaft with engine.
NOTE: DO NOT run engine without ram airflow across radiator for
prolonged periods, as overheating of engine or transmission
may occur.
2) On most models, balance testing may be done by marking
shaft in 4 positions, 90 degrees apart. Place marks approximately 6"
forward of weld, at rear end of shaft. Number marks one through 4.
3) Place screw-type hose clamp so clamp head is in number one
position, and rotate shaft with engine. If there is little or no
change, move clamp head to No. 2 position, and repeat test.
4) Continue procedure until vibration is at lowest level. If
no difference is noted with clamp head moved to all 4 positions,
vibrations may not be drive shaft imbalance.
5) If vibration is lessened but not completely gone, place 2
clamps at that point, and run test again. Combined weight of clamps in
one position may increase vibration. If so, rotate clamps 1/2" apart,
above and below best position, and repeat test.
6) Continue to rotate clamps as necessary, until vibration is
at lowest point. If vibration level is still unacceptable, leave rear
clamp(s) in position and repeat procedure at front end of drive shaft.\
If vibration can be eliminated or reduced to acceptable levels using
this test procedure, send drive shaft out to be balanced.

\003
* D RIV ETR AIN S YSTE M S U NIF O RM IN SPEC TIO N G UID ELIN ES *
1988 Jeep Cherokee
GENERAL INFORMATION
Drivetrain/Transmission Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
Drive/Power Train Assemblies
AUTOMATIC TRANSMISSION/TRANSAXLE ASSEMBLIES
DIFFERENTIAL AND FINAL DRIVE ASSEMBLIES
MANUAL TRANSMISSION/TRANSAXLE ASSEMBLIES
TRANSFER CASE ASSEMBLIES
Drive/Power Train Components
ACTUATORS (ELECTRICAL)
ACTUATORS (VACUUM)
AXLES
BEARINGS AND RACES
BELL CRANKS
BELL HOUSINGS
BUSHINGS (EXTERNAL)
CABLES (SPEEDOMETER)
CABLES (TV, DETENT AND SHIFT)
CARRIER BEARINGS
CLUTCH CABLES AND CABLE HOUSINGS
CLUTCH DISCS (MANUAL TRANSMISSION)
CLUTCH FORKS
CLUTCH LINKAGES (MECHANICAL)
CLUTCH MASTER CYLINDERS
CLUTCH PEDALS
CLUTCH PIVOTS
CLUTCH PRESSURE PLATES
CLUTCH RELEASE BEARINGS
CLUTCH SLAVE CYLINDERS (CONCENTRIC)
CLUTCH SLAVE CYLINDERS (CONVENTIONAL OR EXTERNAL)
COMPANION FLANGES
CONNECTORS
COOLER BYPASS VALVES
COOLER LINES
COOLERS
CV JOINTS
DIP STICK TUBES
DIP STICKS (FLUID LEVEL INDICATORS)
DOWEL PINS, GUIDES AND PILOT HOLES
DRIVE SHAFT FLANGES
DRIVE SHAFTS AND HALF SHAFTS
DUST BOOTS
ENGINE MOUNTS
EXCITER RINGS
FILLER TUBES
FILTERS AND SCREENS

NOTE: Whenever transmission or drivetrain service is performed
that affects the suspension alignment, for example,
removing the engine cradle, it is required that the
alignment be checked and corrected if necessary.
AUTOMATIC TRANSMISSION/TRANSAXLE ASSEMBLIES
AUTOMATIC TRANSMISSION/TRANSAXLE ASSEMBLY INSPECTION








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Condition Code Procedure
Any internal component
failure that requires
removal of the assembly
from the vehicle for
service. ( 1) ........... A ........... ( 2) Require repair or
replacement of the automatic
transmission/transaxle
assembly.
( 1) - It is Required that the torque converter and all other
failure related components be inspected for cause and
condition.
( 2) - For components not requiring removal of the assembly,
refer to the component listing in this document.









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DIFFERENTIAL AND FINAL DRIVE ASSEMBLIES
NOTE: Does not include half shafts.
DIFFERENTIAL AND FINAL DRIVE ASSEMBLY INSPECTION









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Condition Code Procedure
Any internal component
failure that requires
removal of the assembly
from the vehicle for
service. ( 1) ........... A ... Require repair or replacement
of the differential assembly.
( 1) - For components not requiring removal of the assembly,
refer to the component listing in this document.









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MANUAL TRANSMISSION/TRANSAXLE ASSEMBLIES
MANUAL TRANSMISSION/TRANSAXLE ASSEMBLY INSPECTION








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Condition Code Procedure
Any internal component
failure that requires
removal of the assembly
from the vehicle for
service. ( 1) ........... A ... Require repair or replacement
of the manual
transmission/transaxle
assembly.
( 1) - For components not requiring removal of the assembly,

refer to the component listing in this document.








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TRANSFER CASE ASSEMBLIES
TRANSFER CASE ASSEMBLY INSPECTION








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Condition Code Procedure
Any internal component
failure that requires
removal of the assembly
from the vehicle for
service. ( 1) ........... A ... Require repair or replacement
of the transfer case
differential assembly.
( 1) - For components not requiring removal of the assembly,
refer to the component listing in this document.









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DRIVE TRAIN/COMPONENTS
The conditions listed for the components included in this
section assume that the problem has been isolated to the specific
component through proper testing.
ACTUATORS (ELECTRICAL)
ACTUATOR (ELECTRICAL) 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.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted,
affecting performance .. A ........... ( 1) Require repair or
replacement.
Connector melted, not
affecting performance .. 2 ........... ( 1) Suggest repair or
replacement.
Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ ( 2) Require replacement.
Missing ................. C ............ Require replacement.
Noisy ................... 2 .. Suggest repair or 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 .. 1 ........... ( 1) Suggest repair or