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.
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)
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.
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.
CYLINDER BLOCK
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
BLOCK CLEANING
Only cast cylinder blocks should be hot tank cleaned.
Aluminum cylinder blocks should be cleaned using cold tank method.
Cylinder block is cleaned in order to remove carbon deposits, gasket
residue and water jacket scale. Remove oil galley plugs, freeze plugs
and cam bearings prior to block cleaning.
BLOCK INSPECTION
Visually inspect the block. Check suspected areas for cracks
using the Dye Penetrant inspection method. Block may be checked for
cracks using the Magnaflux method.
Cracks are most commonly found at the bottom of the
cylinders, the main bearing saddles, near expansion plugs and between
the cylinders and water jackets. Inspect lifter bores for damage.
Inspect all head bolt holes for damaged threads. Threads should be
cleaned using tap to ensure proper head bolt torque. Consult machine
shop concerning possible welding and machining (if required).
CYLINDER BORE INSPECTION
Inspect the bore for scuffing or roughness. Cylinder bore
is dimensionally checked for out-of-round and taper using dial bore
gauge. For determining out-of-round, measure cylinder parallel and
perpendicular to the block centerline. Difference in the 2 readings
is the bore out-of-round. Cylinder bore must be checked at top, middle
and bottom of piston travel area.
Bore taper is obtained by measuring bore at the top and
bottom. If wear has exceeded allowable limits, block must be honed
or bored to next available oversize piston dimension.
CYLINDER HONING
Cylinder must be properly honed to allow new piston rings to
properly seat. Cross-hatching at correct angle and depth is critical
to lubrication of cylinder walls and pistons.
A flexible drive hone and power drill are commonly used.
Drive hone must be lubricated during operation. Mix equal parts of
kerosene and SAE 20w engine oil for lubrication.
Apply lubrication to cylinder wall. Operate cylinder hone
from top to bottom of cylinder using even strokes to produce 45 degree
cross-hatch pattern on the cylinder wall. DO NOT allow cylinder hone
to extend below cylinder during operation.
Recheck bore dimension after final honing. Wash cylinder
wall with hot soapy water to remove abrasive particles. Blow dry with
compressed air. Coat cleaned cylinder walls with lubricating oil.
DECK WARPAGE
Check deck for damage or warped head sealing surface. Place
a straightedge across gasket surface of the deck. Using feeler gauge,
measure clearance at center of straightedge. Measure across width and