1988 PONTIAC FIERO light

REAR AXLE 481-1
SECTION 4B4
BORG WARNER REAR AXLE
NOTICE: All rear axle attaching fasteners are an
necessary. Do not use a replacement part of lesser
important part in that they could affect the
quality or substitute design. Torque values must
performance of vital parts and systems, and/or
be used as specified during reassembly to assure
could result in major repair expense. They must
proper retention of all parts. (There is to be no
be replaced with one of the same part number or
welding as it may result in extensive damage and
with an equivalent part if replacement becomes
weakening of the metal.)
CONTENTS
General Description ............................... 4B 1- I
......... Standard Rear Axle ................... ..... 4B 1 - 1
General Information ............................. .... 4B 1- 1
Limited-Slip Rear Axle .............................. 4B 1-2
Operation
............................................ 4B 1-3
Diagnosis and Testing .......................... 4B 1-2
Axle Noises
..................... .... .................. 4B 1-2
Gear Noise
................................... .... .. 4B 1-4
Bearing Noise
......................... ...... ... 4B 1-4
Rear Wheel Bearing Noise ..................... 4B 1-4
Knock At Low Speeds
....................... ..... 4B 1-4
Backlash Clunk
................................... 4B 1-4
Diagnosis
................................................ 4B 1-4
Pre-Repair Investigation and Trouble
Diagnosis
....................... .. .................... 4B 1-4
...................................... On-Vehicle Sewice 4B 1-7
Carrier Cover and Gasket .......................... 4B 1-7
.............. Axle Shaft ......................... ....., 4B 1-7
Tooth Contact Pattern Test
................... 4B 1-8
Procedure
.................... .. ...................... 4B 1-8
Effects of Increasing Load on
Teeth Contact Pattern
......................... 4B 1-8
Adjustments Affecting Tooth
................................................ Contact 4B 1-8
Effects of Pinion
Postion on Tooth Pattern
............................................... 4B
1-8
Pinion Oil Seal and Companion
Flange Replacement
................... .. ...... 4B 1-8
Rear Wheel Bolt
........................................ 4B 1 - 10
Rear Axle Assembly
................................... 4B I - 10
Unit Repair
............................................... 4Bl-1 1
Drain Rear Axle Assembly ........................ 4B I - I I
Differential Assembly ............................. 4B 1 - 1 1
Hypoid Pinion & Pinion Bearings .......... 4B 1- I I
Four Pinion Standard Differential
Assembly
....................... ... ........... 4B 1 - 1 3
Inspection
............................................ 4B 1 - I:!
Differential Assembly .......................... 4B 1 - 14
Differential Bearing Preload Spacer
................... ...................... Selection .. 4B I - 11
.................................................. Pinion 4B 1 - 15
Operation of Limited Slip Rear Axle
........................................... (Cone Type) 4B 1 - 17
Checking Limited-Slip Function
............ 4B 1 - 17
......................... Limited Slip Differential 4B 1 - 18
.............. Disassembly Inspection Chart 4B
1- 18
......................... Limited Slip Differential 4B I - 1 X
............................................. Specifications
4B 1- 19
Axle Code Identification Chart
............ 4B 1-19
............................................. Special Tools 4B 1-20
GENERAL DESCRIPTION
STANDARD REAR AXLE All parts necessary to transmit power from the
propeller shaft to the rear wheels are enclosed in a
The rear axle assembly is of the semi-floating type salisbury type axle housing (a carrier casting with tubes
in which the car weight is carried on the axle housing.
pressed and welded into the carrier to form a complete The rear axle assembly is designed for use with an open carrier and tube assembly). A removable steel cover drive line and coil springs. The rear axle has a hypoid bolted to the rear of the carrier permits service of the type ring gear and pinion with the centerline of the rear axle without removing the entire assembly from
pinion gear below the centerline of the ring gear.
the car.
GENERAL INFORMATION
NOTICE: Most rear axle service repairs can be
Two pre-loaded tapered roller bearings support the
made with the rear axle assembly in the car, by
hypoid pinion gear in the carrier. The inner race of the
raising the rear end of the car with the rear axle
rear bearing is a tight press fit on the pinion stem. The
hanging on the shock absorbers.
inner race of the front bearing combines a light press
fit to a close sliding fit on the pinion flange end of the
A universal joint connects the rear end of the pinion stem. The outer race of each bearing is pressed
propeller shaft to a companion flange having a splined against a shoulder recessed in the carrier. Tightening
end which fits over and drives the
hypoid pinion gear. the pinion nut compresses a collapsible spacer which

4819 REAR AXLE
bears against the inner race of the front bearing and a
shoulder on the pinion stem. This spacer is used to
enable accurate bearing pre-load adjustment and
maintain a pre-load on both front and rear pinion
bearings, Adjustment of the fore and aft position of the
pinion is obtained by placing a shim between the rear
pinion bearing cup and axle housing. The differential
case is of two-piece construction and is supported in
the carrier by two tapered roller side bearings. Pre-load
rear axle case by inserting shims between the bearings
and the carrier. The rear axle case assembly is
positioned for proper ring gear to pinion backlash by
varying the shim thickness from side to side. The ring
gear is bolted to the case. Two side gears have splined
bores for driving the axle shafts. They are positioned
to turn in counterbored cavities in the case. The four
rear axle pinions have smooth bores and are held in
position by a pinion cross shaft, mounted and locked
in the rear axle case. All six gears are in mesh with each
other and because the pinion gears turn freely on their
shaft, they act as idler gears when the rear wheels are
turning at different speeds. The pinions and side gears
are backed by steel thrust washers.
LIMITED-SLIP REAR AXLE
The operation of the Limited-Slip differential is
the same as the standard differential, except that there
is additional friction provided by the conical clutches.
Under ordinary driving and cornering conditions, the
cones slip, allowing the outside wheel to turn faster
than the inner. Under poor traction conditions, such as
ice, snow, or loose gravel under one driving wheel, the
increased friction provided by the cones increases the
driving torque available to the wheel with the better
traction. The cones are spring loaded to provide the
increased driving torque under extremely low traction
conditions.
Operation
When the vehicle turns a corner, the outer rear
wheel must turn faster than the inner wheel. The inner
wheel, turning slower than the outer wheel, slows its
differential side gear (as the axle shaft is splined to the
side gear) and the differential pinion gears will roll
around the slowed differential side gear, driving the
other differential side gear and wheel faster.
DIAGNOSIS AND TESTING
Many noises reported as coming from the rear
axle assembly actually originate from other sources
such as tires, road surfaces, front wheel bearings, axle
bearing, engine, transmission, muffler or body
drumming. A thorough and careful check should be
made to determine the source of the noise before
disassembling the rear axle. Noise which originates in
other places cannot be corrected by adjustment or
replacement of parts in the differential. It should also
be remembered that rear axle gears, like any other
mechanical device, are not absolutely quiet and should
be accepted as being commercially quiet unless some
abnormal noise is present.
To make a systematic check for axle noise under
standard conditions, observe the following:
1. Select a level smooth asphalt road to reduce tire
noise and body drumming.
2. Check rear axle lubricant to assure correct level,
then drive car far enough to thoroughly warm up
rear axle lubricant, approximately 10 miles.
3. Note speed and RPM at which noise occurs. Stop
car and put transmission in neutral. Run engine
slowly up and down through engine speeds,
corresponding to car speed at which noise was
most pronounced, to determine if it is caused by
exhaust, muffler roar or other engine conditions.
4. Tire noise changes with different road surfaces,
but rear axle noise does not. Temporarily
inflating all tires to approximately 50 pounds
pressure
for test purposes only will materially
alter noise caused by tires, but will not affect noise
caused by rear axle. Rear axle noise usually stops
when coasting at speeds under 30 miles per hour;
however, tire noise continues, but with lower
tone, as car speed is reduced. Rear axle noise
usually changes when comparing acceleration
and coast, but tire noise remains about the same.
Distinguish between tire noise and rear axle noise
by noting if noise varies with various speeds or
sudden acceleration and deceleration; exhaust
and axle noise show variations under these
conditions while tire noise remains constant and
is more pronounced at speeds of 20 to 30 miles
per hour. Further check for tire noise by driving
car over smooth pavements or dirt roads (not
gravel) with tires at normal pressure. If noise is
caused by tires, it will noticeably change or
disappear and reappear with changes in road
surface.
5. Loose or rough front wheel bearings will cause
noise which may be confused with rear axle
noises; however, front wheel bearing noise does
not change when comparing drive and coast.
Light application of brakes while holding car
speed steady will often cause wheel bearing noise
to diminish, as this takes some weight off the
bearing. Front wheel bearings may be easily
checked for noise by jacking up the wheels and
spinning them, also by shaking wheels to
determine if bearings are loose.
6. Rear suspension rubber bushings and spring
insulators dampen out rear axle noise when
correctly installed. Check to see that no metallic
contact exists between the spring and spring seat
opening in frame or between upper and lower
control arm bushings and frame or axle housing
brackets. The track bar and torque arm must be
bolted securely. Metal-to-metal contact at those
points may result in telegraphing road noise and
normal axle noise which would not be
objectionable if dampened by bushings.
AXLE NOISES
After the noise has been determined as being in
the axle by following the above appraisal procedure,
the type of axle noise should be determined to aid in
making repairs if necessary.

481-4 REAR AXLE
Gear Noise
Gear noise (whine) is audible from 20 to 55 mph
under four driving conditions:
1. Light Acceleration - Accelerate slowly.
2. Road Load
- Car
driving load or constant speed.
3. Float - Using enough throttle to keep the car from
driving the engine
- car slows down gradually but
engine still pulls slightly.
4. Coast - Throttle closed and car in gear.
Bearing Noise
Bad bearings generally produce more of a rough
growl or grating sound, rather than the whine typical
of gear noise. Bearing noise frequently "wow-wows" at
bearing rpm, indicating a defective pinion or rear axle
case side bearing. This noise could easily be confused
with rear wheel bearing noise. Inspect and replace as
required.
Rear Wheel Bearing Noise
A rough rear wheel bearing produces a noise
which continues with car coasting at low speed and
transmission in neutral. Noise may diminish some by
gentle braking. With rear wheels jacked up, spin rear
wheels by hand while listening at hubs for evidence of
rough (noisy) wheel bearing.
Knock At Low Speeds
Low speed knock can be caused by worn
universal joints or a side gear hub counterbore in a case
that has worn oversize. Inspect and replace universal
joint or case and side gear as required.
Backlash Clunk
Excessive clunk with acceleration and deceleration
is caused by worn differential pinion gear shaft, excessive
clearance between axle shaft and side gear splines, exces-
sive clearance between side gear hub and counterbore in
case, worn pinion and side gear teeth, worn thrust washers
and excessive drive pinion and ring gear backlash. Re-
move worn parts and replace as required, selecting close
fitting parts when possible. Adjust pinion and ring gear
backlash.
DIAGNOSIS
1. Noise
is the same in "Light Acceleration" or
"Coast".
a. Road noise.
b. Tire noise.
c. Front wheel bearing noise.
d. Rear axle bearing noise.
2. Noise changes on a different type of road.
a. Road noise.
b. Tire noise.
3. Noise tone lowers as car speed is lowered.
a. Tire noise.
b. Front
wheel bearings and rear axle bearings.
c. Gear noise.
4. Similar noise is produced with car standing and
driving. a.
Engine noise.
b. Transmission noise.
c. Exhaust noise.
5. Vibration.
a. Rough rear axle bearing.
b. Unbalanced or damaged propeller shaft.
c. Tire unbalance.
d. Worn universal joint in propeller shaft.
e. Mis-indexed propeller shaft at pinion
flange.
f. Pinion flange runout too great.
6. A knock or click approximately every two
revolutions of the rear wheel.
a. A rear axle bearing.
b. Worn case.
7. Noise most pronounced on turns.
a. Rear axle side gear and pinion noise,
differential gear noise.
b. Axle bearings.
8. A continuous low pitch whirring or scraping
noise starting at relatively low speed.
a. All bearing noise.
9. Drive noise, coast noise or float noise.
a. Ring
and pinion gear noise.
b. Front
pinion bearing noise, coast or drive.
c. Axle bearing noise.
10. Clunk
on
acceleration or deceleration.
a. Worn
rear axle pinion shaft splines.
b. Side
gear hub counterbore in case worn
oversize.
c. Worn U-joints.
d. Excessive transmission backlash.
e. Worn axle shaft splines.
11. Chatter on turns.
a. Wrong
lube in rear axle.
b. Clutch
cone worn or spalled.
12. Clunk
or knock on rough road operation.
a. Worn suspension bushings.
PRE-REPAIR INVESTIGATION AND TROUBLE
DIAGNOSIS
A carefull diagnosis of the rear axle prior to
disassembly will often reveal valuable information as to
the extent and type of repairs or adjustments necessary.
Since frequent causes of axle noises are improper
backlash, pinion bearing pre-load, or side bearing
pre-load, or a combination, a few simple adjustments
may be all that are necessary to correct a problem.
Before disassembling the rear axle, the following
checks should be made with the results recorded and
analyzed: 1) Backlash;
2) Total Assembly Preload; 3)
Tooth Contact Pattern Test; 4) Fluid Level; and 5)
Fluid Contamination.
If axle shaft end play is excessive then check
bearings, retainer, and bolts securing backing plate.
The axle bearings could be worn and need replacement.
The four bolts or nuts securing the brake backing plate
may be loose, stripped, or missing. If the inner bearing
retainer worked loose it must be replaced.
Use care at all times to keep dirt and other foreign
matter, such as grinder dust, soot or sand, away from
differential to prevent possibility of subsequent failure.

REAR AXLE 481-7
ON-VEHICLE SERVICE
CARRIER COVER AND GASKET
Remove or Disconnect
1. Having
a container in place remove drain plug
with tool
J-35117,remove cover bolts and pry
cover loose to drain lubricant.
2. Make sure both
gasket sealing surfaces are clean.
Install or Connect
Use cover gasket (do not assemble with
sealant alone).
NOTICE: Apply locktite part No. 573, GM Part
Nos. 1052080, or 1052279 or equivalent to cover
bolts before installing cover. If sealant is not applied
bolts may loosen causing fluid leak and damage to
rear axle assembly.
1. Torque cover bolts in a crosswise pattern to
insure uniform draw on gasket. Torque
26 N.m
(20 1b.ft.).
2. Fill with lubricant to bottom of filler plug hole.
Refer to specifications for correct lubricant usage
and quantity.
AXLE SHAFT
Remove or Disconnect
1. Wheel
and brake components as necessary.
2. The
four nuts holding the brake anchor plate and
outer bearing retainer.
3. Withdraw the axle shaft and wheel bearing assem-
bly using axle shaft remover
J 21579 and slide
hammer
J 2619-01 (Fig. 4).
Fig. 4 Axle Shaft Removal
4. Inner
bearing retainer and bearing from axle
shaft. To do this carefully split the retainer with
a chisel and remove from shaft. Press off bearing
with tool
5-22912-01 from axle. Discard bearing
and seal (Fig. 5).
Fig. 5 Bearing and Seal Removal
Examine axle shaft. If axle shaft is in satisfactory
condition it may be re-used.
Important
Bearings and inner bearing retainers which
have been removed from an axle shaft
should not be re-used.
Install or Connect
1. Place the outer bearing retainer on the axle shaft.
Important
Right and left hand axle shaft seals are
different in construction. Right hand seal is
black banded with right hand ridges. Left
hand seal is gold banded with left hand
ridges. The part numbers designate left and
right sides.
2. Place the oil seal on the axle shaft ensuring that
the spring side of the oil seal faces the center of
the axle. Lubricate seals lips with a light coat of
grease. Note use of excessive amounts of grease
may damage seal.
3. Press wheel bearing and inner bearing retainer hard
against bearing shoulder on axle shaft with tool
J 8853-01, ensuring that the retainer is tight against
the bearing and with
O.D. chamfer towards
bearing.
4. Place the axle shaft through the brake anchor
plate and align axle shaft and side gear splines.
5. Once the splines have been engaged in the side
gears the wheel bearing and oil seal may be
pushed into the housing.
A light coat of grease on
the seal outside diameter will assist in installation.
Tighten four backing plate bolts alternately. Use
new locknuts on bolts. (Refer to specifications).
NOTICE: If a limited-slip differential is used
ensure that both axle shaft splines are fully
engaged before the axle shafts are rotated. This is
to mainatain spline alignment, refer to limited-slip
instructions.

481.8 REAR AXLE
6. Replace
brake components and wheel.
7. Tighten wheel nuts and lower vehicle.
Tooth Contact Pattern Test
The side of the ring gear tooth which curves
outward, or is convex, is referred to as the "drive" side.
The concave side is the "coast" side. The end of the
tooth nearest center of ring gear is referred to as the
"toe" end. The end of the tooth farthest away from the
center is the "heel" end. Toe end of tooth is smaller
than heel end.
It is very important that tooth contact be tested
before the rear axle carrier assembly is disassembled.
Variations in the carrier or pinion rear bearing may
cause the pinion to be too far away from, or close to,
the ring gear. Thus, the tooth contact must be tested
and corrected, if necessary, or the gears may be noisy.
Procedure
1. Drain
oil out of carrier and carefully clean each
tooth of ring gear.
2. Apply parking brake until a torque of 54 to 70
N-m (40-50 lb. ft.) is required to turn the pinion.
3. Tighten bearing cap bolts to 52 N-m (40 lb. ft.).
4. Use gear marking compound part number
1052351 or equivalent and apply this mixture
sparingly to all ring gear teeth, using a medium
stiff brush. When properly used, the area of
pinion tooth contact will be visible when hand
load is applied.
A test made without loading the gears will not
give a satisfactory pattern. Turn pinion flange
with wrench so that ring gear rotates five full
revolutions, then reverse rotation so that ring
gear rotates five
revolutio~ls in opposite direction.
5. Observe pattern on ring gear teeth and compare
with Fig.
6.
Effects of Increasing Load on Teeth Contact
Pattern
When "load" on ring and pinion gear is
increased, such as when car is accelerated forward
from standstill or from normal drive, the tooth contact
will tend to spread out and, under very heavy load, will
extend from near toe to near heel on the drive side. The
entire contact also tends to shift toward heel under
increasingly heavier loads and will become somewhat
broader with respect to tops and bottoms of teeth. The
patterns obtained by this tooth contact pattern test
approximate a light load and, for this reason, they will
extend only about halfway.
The important thing to note is that the contact
pattern is centrally located up and down on the face of
the ring gear teeth.
Adjustments Affecting Tooth Contact
Two adjustments can be made which will affect
tooth contact pattern, backlash and position of drive
pinion in carrier. The effects of bearing pre-loads are
not readily apparent
on (hand-loaded) tooth contact
pattern tests; however, these adjustments should be within
specifications before proceeding with backlash
and drive pinion adjustments.
Backlash is adjusted by means of the side bearing
adjusting shims, which moves the entire case and ring
gear assembly closer to, or farther from, the drive
pinion (the adjusting shims are also used to set side
bearing pre-load). The position of the drive pinion is
adjusted by increasing or decreasing the shim thickness
between the rear pinion cup and axle housing
. The
shim is used in the rear axle case to compensate for
manufacturing tolerances. Increasing shim thickness
will move the pinion closer to centerline of the ring
gear. Decreasing shim thickness will move pinion
farther away from centerline of the ring gear.
Effects of Pinion Position on Tooth Pattern
When the drive pinion is too far away from
centerline of the ring gear, the pattern will be a high
heel contact on the drive side and high toe contact on
coast side (Fig. 6). Moving the pinion closer to
centerline of the ring gear by increasing shim thickness
will cause the high heel contact on drive side to lower
and move toward the toe; the high toe contact on coast
side will lower and move toward the heel.
When the pinion is too close to the centerline of
the ring gear, the pattern will be a low toe contact on
drive side and a low heel contact on the coast side.
Moving the pinion farther away from the ring gear by
decreasing shim thickness will cause low toe contact on
drive side to raise and move toward the heel; the low
heel contact on coast side will raise and move toward
the toe.
PINION OIL SEAL AND COMPANION FLANGE
REPLACEMENT
Remove or Disconnect
1. Mark the propeller shaft and companion flange
so they can be reassembled in the same position.
Remove four nuts and lock washers from two
saddles retaining
U-joints to companion flange
and remove propeller shaft.
2. Measure and record preload at pinion - this
includes pinion bearing, differential bearings,
effect of grease and oil seal. (Figure
7).
3. Pinion nut with companion flange remover
J-8614-01. (Figure 8).
4. Companion flange with companion flange
remover
5-8614-01. (Figure 8).
5. Seal and discard.
NOTICE: Before installing a new seal examine the
surface of the companion flange on which the seal
runs. Should this surface be damaged or the splines
excessively worn, a new companion flange should
be installed. Also examine the housing bore and
remove any nicks or burrs.

REAR AXLE 481-9
A central face lengthwise position is shown here representing
COAST SlDE the limit of acceptability of the contacts position towards DRIVE SIDE the heel.
ACCEPTABLE HEEL
CONTACTS
DRIVE SlDE COAST
SlDE
HEEL END
The contact should fade out at least 5mrn before the heel
end face,
A central profile position is shown and is acceptable alrhough a low contact is preferred.
The center of the contact is located at
518 of the face width
from the toe and it does not approach the heel end by less
than
5mm,
A high contact pattern as shown is preferred for coast side
contacts which tend to be towards the heel.
A central profile position is acceptable providing pinion face
angle edge lines do not appear low on the gear.
The contact begins almost at the toe end face and extends in
length by approx, half the facewidth.
A slightly lower contact pattern as shown is preferrable although a centrally located profile postion will suffice.
The contact begins almost at the toe end face and may appear
pointed as shown although a square end is equally acceptable.
The total length of contact is approx.
112 of the face width.
A high profile position is desirable although a central profile
is acceptable.
IDEAL
CONTACTS
DRIVE SIDE COAST SIDE A central toe lengthwise position and a slightly lower contact
pattern in the profile position. Total length about 518 of gear
facewidth.
Note the clearance of about
1 rnrn between the contact and the
toe and along the top face angle line.
A centrally located lengthwise position and a slightly higher
contact pattern in the profile position. Total length about
518 of the gear facewidth.
Note the clearance between the contact and the face angle line
of the gear.
ACCEPTABLE
TOE CONTACTS
Fig. 6 Gear Tooth Contact Pattern

481-10 REAR AXLE
LB. IN. TORQU
520021-481
Fig. 7 Bearing Preload Measurement
Fig.
8 Companion Flange Removal
Install or Connect
1. Lubricate oil seal lips with a light cover of grease.
2. Install
new seal in carrier, flush to
0.25mm (0.
010) below surface with pinion seal installer
5-351 19. (Fig. 9).
Fig. 9 Pinion Seal Installation
3. Companion flange and tighten nut to achieve the
bearing preload as measured in Step
2 above plus
0.5
N-m (5 lb. in.) to allow for the new seal with
companion flange installer J-86 14-0 1 (Fig.
8).
NOTICE: If pinion nut is over tightened by more
than 0.5
N.m (5 lb. in.) as in step 3 then the unit
should be rebuilt with a new collapsible spacer as
in step 3.
4. Align propeller shaft on locating marks and
connect propeller shaft with 2
U saddles and 4
bolts and lockwashers to companion flange.
5. Fill with lubricant to bottom of filler plug hole.
Refer to specifications for correct lubricant usage
and quantity.
6. Filler plug.
REAR WHEEL BOLT
Remove or Disconnect
1.
Raise vehicle on hoist allowing axle to hang
freely.
2. Wheel, tire and caliper and rotor.
3. Using Tool J 6627-A press out stud (Fig. 10).
Fig. 10 Removing Wheel Stud
I Install or Connect
1. Place new stud in axle flange hole. Slightly start
stud serrations in hole by firmly pressing back of
stud with your hand.
2. Place a flat washer on the stud and install a lug
nut with flat side first (tapered face outboard).
Tighten on lug nut drawing stud into flange until
stud head is bottomed on back side of flange. (Fig.
11).
3. Remove lug nut.
4. Rotor and caliper, wheel and tire.
5. Lower vehicle and remove from hoist.
REAR AXLE ASSEMBLY
It is not necessary to remove the rear axle
assembly for any normal repairs. However, if the
housing is damaged, the rear axle assembly may be
removed and installed using the following procedure.
I Remove or Disconnect .I
1. Hoist car and support at frame. Hoist must
remain under rear axle housing.
2. Wheels and lug nuts.

4B1-12 REAR AXLE
NOTICE: Mark differential case halves with
alignment mark before disassembly because they
could be assembled
180" off from original position.
Fig. 12 Differential Assembly Removal
3. Pry front seal out of carrier and remove bearing
cone. Discard seal.
4. Rear pinion bearing with tool J 21493-B and
press. Clamp tool around pinion shaft holding
bearing and press pinion shaft off rear pinion
bearing. (Fig. 13).
I
5. Drive rear bearing cone out of carrier with soft
brass drift, and remove selective spacer washer.
Remove or Disconnect
Four Pinion Standard Differential Assembly
(Figure
14)
1. Ring gear bolts.
1 Important
MCTICE: Left hand thread ring gear bolts.
2. Ring gear from differential housing, with soft face
hammer.
3. Drive out three differential pinion cross shaft
retaining pins.
4. Drive three differential pinion shafts from
housing, long shaft first.
5. Split differential case by holding one side and
tapping against other side with long soft drift.
6. Four differential pinions, side gears and thrust
washers from housing.
7. Differential case bearings with tool 5-22888-D
(Fig. 15).
Inspection
All components should be cleaned and inspected
for excessive wear.
Cleaning of bearings should be performed with
new solvent and should be followed up by coating
the bearing with light engine oil
to prevent
rusting.
1. I-Iypoid gear set
Important
a.
Examine for scuffed or chipped teeth. A
gear set cannot be made to run quiet if teeth
are scuffed.
b. Ring gear bore and back face should be
clean and free from burrs. The rear bearing
preload abutment faces on the
hypoid
pinion should be clean and free from burrs.
c. Examine the thread and bearing journal of
the
hypoid pinion.
2. Bearings
Important
a. Cups should have an even wear pattern and
be free from flaking or pitting. Ensure that
the abutment faces are clean and free from
burrs or raised metal.
b. The cone assemblies should feel smooth
when turned in the cups.
c. The assembly should be free from loose
particles. No cracks should be present in the
roller cages and the bores should contain no
tears.
3. Differential pinions and side gears.
Important
a. Examine the teeth for cracks and hard
contact marks. It is advisable to check the
teeth for cracks and excessive wear. The
side gear splines should be checked for
excessive wear.
b. Check the side gear journals and back thrust
for scoring.
c. The
differential pinion bores and spherical
thrust surfaces should be smooth and free
from scores.
4. Thrust washers should be free from cracks, nicks
or burrs.
5. Differential pinion cross shafts cannot be bent
and the pinion gear mating surfaces must not be
scored.