1988 JEEP CHEROKEE Service Repair Manual

Lubricate all parts with gear oil. On one-piece case, place side gears
and new thrust washers in case. Place differential pinions and new
thrust washers in case. Rotate side gears until holes in pinion gears
and washers line up with holes in case. Install differential pinion
shaft. Install lock pin after aligning hole in shaft with hole in
case. Peen edge of hole to keep pin in place.
6) On 2-piece case, Install side gears and new washers with
pinion gears and cross shaft into half of case that is flanged. Put
top half of case on bottom half. Align scribe marks made before
disassembly. Tighten all bolts finger tight. Tighten bolts alternately
to 65-70 ft. lbs. (88-95 N.m).
7) On all one and 2-piece case units, inspect ring gear and
case for any burrs or nicks. Install ring gear and tighten NEW ring
gear bolts evenly in alternating pattern to specification.
8) Install Master Bearings into case. Use (D-135) for Model
44 or (D-117) for Models 60, 61, 70 and 80. Install differential case
in carrier. Install and tighten side bearing caps finger tight over
master bearings. Caps must be in same location as marked during
disassembly. Mount dial indicator on carrier with indicator tip
against back of ring gear.
9) Pry case assembly to one side of carrier. Zero dial
indicator and pry case in opposite direction. See Fig. 13. Record
reading. This indicates thickness of shim pack necessary to eliminate
clearance between case and side bearing races.
10) Actual placement of shim pack and necessary preload will
be calculated after drive pinion is installed and pinion depth has
been determined. Remove dial indicator. Remove bearing caps and
differential case from carrier.
NOTE: If new differential side and pinion gears are used with new
washers, gear backlash should be correct due to close
machine tolerances. If old gears and/or washers are used,
gear backlash must be checked.
Fig. 13: Measuring Differential Case End Play
NOTE: If original ring and pinion is to be used, measure old shim
packs and make up packs of same dimensions with new shims.
Baffles are considered part of shim pack.

PINION DEPTH
1) Depth Gauge Set (D-271) is used to determine pinion depth\
.
Place Master Pinion Block (D-139 on Model 44; D-120 on Model 60 and
61; D-137 on Model 70; T80T-4020-F42 on Model 80) in pinion bore of
carrier. Put Arbor Discs (D-115-4-44 on Model 44; D-116-2 on Models
60,61 and 70; (T88T-4020-A) on Arbor (D-115-3). Install arbor in
carrier with discs riding in bearing bore.
2) Put Pinion Height Block (D-115-1-44 on Model 44; D-116-1
on Models 60, 61, 70 and 80) on top of master pinion block with side
against arbor. Place Scooter Block (115-2) with Dial Indicator (D-106\
-
5) on small step of pinion height block. Zero dial indicator with
scooter block flat on pinion height block.
3) Move scooter block so dial indicator tip touches arbor.
Move block back and forth (perpendicular to arbor) to get highest
reading. This reading, plus or minus value etched on pinion head, is
thickness of shim pack necessary for pinion bearing.
4) On Model 80, Use Gauge Tube (D81T-4020-F51) and Gauge
Block (D81T-4020-F56) to determine required thickness of shim pack.
5) On all models, measure shims separately with micrometer.
If baffle is used, its thickness must be included in shim pack. This
is also true if slinger is used between inner bearing and head of
pinion shaft. Place pinion height shim pack in carrier bore for inner
bearing race. Drive bearing race into carrier, making sure cup is
fully seated.
PINION BEARING PRELOAD
1) Drive outer pinion bearing into carrier housing. Press
inner pinion bearing onto pinion shaft using Press Tube (C-3095-A).
Ensure bearing seats fully. Insert pinion shaft into carrier. Install
outer bearing, slinger (if equipped), flange, washer and nut.
NOTE: Pinion preload shims and oil seal should NOT be installed at
this time.
2) Using an INCH lb. torque wrench, tighten pinion nut until
10 INCH lbs. (1.13 N.m) rotational torque is required to move pinion
shaft. Recheck pinion depth with arbor and discs at this time. Place
pinion height block on face of pinion shaft.
3) Place dial indicator on small step of height block for
Model 44, 60 and 61 axles. Place dial indicator on high step of block
for Models 70 and 80 axles. Zero dial indicator and move it across
arbor to get highest reading. If reading is within .002" (.05 mm) of
etching on pinion face, pinion depth is correct.
NOTE: If pinion depth is not with .002" (.05 mm) of etched number
on face of pinion, shim pack under inner bearing race must
be changed before proceeding with differential settings.
4) Remove pinion nut, washer, flange, slinger and outer
bearing. Place preload shims (removed during disassembly) on pinion.
Install bearing and slinger. After lightly coating lips with gear oil,
install pinion seal in carrier housing. Install flange, washer and NEW
pinion nut. Tighten nut to specification. See TORQUE SPECIFICATIONS
table at end of this article.
5) Using an INCH lb. torque wrench, measure preload
(rotational torque) of pinion shaft. Rotational torque required to
keep pinion shaft turning freely and smoothly should be 20-40 INCH
lbs. (2.3-4.5 N.m). If preload needs to be increased, remove a few
shims and recheck. To decrease preload, add a few shims and recheck.
See Fig. 14 .

Fig. 14: Carrier Housing Shim Positioning
DIFFERENTIAL BEARING PRELOAD
1) Install differential case in housing with master bearings

on case. Set up dial indicator in same position as when case end play
was checked. See Fig. 13. Press ring gear toward pinion head while
rocking ring gear so teeth mesh fully. Zero dial indicator while
holding ring gear into pinion gear.
2) Press differential case (ring gear) away from pinion gear\
.
Repeat until dial indicator gives same reading each time. This figure
is shim pack thickness necessary between case and side bearing on ring
gear side. Remove dial indicator and differential from carrier. Remove
master bearings from case.
3) Put calculated shim pack on hub of case at ring gear side.
Place side bearing on hub. Use Bearing Installer (C-4025A) and Handle
(C-4171) to drive bearing onto case until it is seated. Take remaining\
shim pack as determined from case end play measurement and install
pack on opposite side of case from ring gear.
4) Add .015" (.38 mm) thickness to shim pack opposite ring
gear to provide side bearing preload. Drive side bearing onto case
with installer and handle. Install spreader and dial indicator on
carrier housing. Spread housing .015" (.38 mm). Put side bearing races\
onto side bearings. Install differential case into carrier.
RING & PINION BACKLASH
1) Install side bearing caps, making sure reference marks
made on caps and carrier match. Tighten cap bolts to 80 ft. lbs. (108
N.m). Check backlash between ring and pinion gears at 3 points spaced
equal distance on ring gear. See Fig. 15.
Fig. 15: Measuring Backlash Between Ring & Pinion Gears
2) Backlash reading between ring and pinion gears should be
.004-.009" (.10-.23 mm). Maximum variation between readings at 3
points is .002" (.05 mm). If backlash is too high, move ring gear

closer to pinion gear. If backlash is too low, move ring gear away
from pinion gear.
3) To change backlash readings, move shims from one side of
differential case to other. When backlash adjustment is completed,
check tooth contact pattern. See GEAR TOOTH CONTACT PATTERNS in this
section. Pattern should be correct if assembly and adjustments have
been done properly.
4) When differential is complete and correctly adjusted,
install new cover gasket and cover. Tighten cover bolts to 30-40 ft.
lbs. (41-54 N.m). Fill assembly with hypoid lubricant.
AXLE ASSEMBLY SPECIFICATIONS TABLE









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Application Specifications In. (mm)
Pinion Gear Depth (Nominal Dimension)
Model 44 ................................. 2.625 (66.68)
Model 60 & 61 ............................ 3.125 (79.38)
Model 70 & 80 ............................ 3.500 (88.90)
Ring Gear Backlash ................... .004-.009 (.10-.23)
Side Bearing Preload .......................... .015 (.38)
INCH lbs. (N.m)
Pinion Bearing Preload
New Bearings ........................... 20-40 (2.3-4.5)
Used Bearings .......................... 10-20 (1.1-2.3)









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TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE








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Applications Ft. Lbs. (N.m)
Axle Flange-to-Hub Bolt
Model 44 ...................................... 35 (48)
Models 60 & 61 ................................ 55 (75)
Model 70 & 80 ................................ 85 (115)
Pinion Shaft Flange Nut
Models 44 & 70 .............................. 210 (285)
Models 60 & 61 .............................. 270 (367)
Model 80 ............................ 440-500 (597-678)
Ring Gear-to-Case Bolt
Model 44 ...................................... 55 (75)
Models 60, 61, & 70 ......................... 110 (149)
Model 80 ............................ 145-165 (196-223)
Side Bearing Cap Bolt ........................... 80 (108)
Front Axle
Cherokee, Comanche, & Wagoneer
Axle Shaft Nut ............................. 175 (237)
Disconnect Housing Bolt ...................... 10 (14)
Hub-to-Knuckle Bolt ......................... 75 (102)
Lower Control Arm Bolt ..................... 133 (180)
Lower Shock Mount Bolt ....................... 14 (19)
Drive Shaft Bolt ............................. 14 (19)
Stabilizer Bar Link Bolt ..................... 70 (95)
Tie Rod Nut ............................ 25-45 (34-61)
Upper Control Arm Bolt ....................... 37 (50)
Wheel Lug Nut ............................... 75 (102)
Grand Wagoneer
Leaf Spring "U" Bolt Nut ................... 100 (136)
Lower Shock Mount Bolt ....................... 45 (61)

Drive Shaft Bolt ............................. 16 (22)
Spindle Attaching Nut ........................ 65 (88)
Tie Rod Nut .................................. 60 (80)
Wheel Lug Nut ............................... 80 (108)









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DRIV E A XLE R ATIO ID EN TIF IC ATIO N

1988 J e ep C hero ke e
1988 Drive Axles - Axle Ratio Identification
Jeep
IDENTIFICATION
Front and rear axle identification number is cast into left
side of cover or into axle housing, adjacent to housing cover.
JEEP FRONT AXLE RATIO IDENTIFICATION









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Application Ratio
Cherokee, Comanche,
Grand Wagoneer & Wagoneer .......... 3.07:1, 3.55:1, 4.10:1, 4.56:1
Wrangler .................... 3.07:1, 3.54:1, 3.55:1, 4.10:1, 2.73:1









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JEEP REAR AXLE RATIO IDENTIFICATION








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Application Ratio
Cherokee, Comanche,
Grand Wagoneer & Wagoneer .......... 3.08:1, 3:55:1, 4.11:1, 4.56:1
Wrangler .................................... 3.08:1, 3.55:1, 4.11:1









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DRIV E A XLE - S TA N DAR D

1988 J e ep C hero ke e
1988 DRIVE AXLES
Jeep 7 9/16" & 8 7/8" Ring Gear
All Models
DESCRIPTION
The rear axle assembly is a hypoid gear type with integral
carrier housing. The standard axle uses a 7 9/16" (192 mm) diameter
ring gear. The heavy duty axle uses an 8 7/8" (225 mm) diameter ring
gear. See Fig. 1.
IDENTIFICATION
Axle assembly has 10-bolt rear cover. The axle ratio and ring
and pinion gear tooth combinations are stamped on a tag attached to
differential housing cover.
AXLE RATIO IDENTIFICATION









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Axle Ratio Tooth Combinations Ring Gear Diameter
3.31:1 ................. 13/43 ............. 7 9/16" (192 mm)
3.54:1 ................. 13/46 ............. 7 9/16" (192 mm)
4.11:1 ................. 9/37 .............. 7 9/16" (192 mm)
4.10:1 ................. 10/41 .............. 8 7/8" (225 mm)









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Fig. 1: Exploded View of Rear Axle Assembly
REMOVAL & INSTALLATION