1988 PONTIAC FIERO oil

TIRES AND WHEELS 3E-9
Another method is to dismount the tire and
rotate it 180 degrees on the rim. It is important that
this be done on tire and wheel assemblies which are
known to be causing a vibration as it is just as likely to
cause good assemblies to vibrate.
Refer to Section 3, "Vibration Diagnosis" for
more details.
ALUMINUM WHEEL CLEANING
Aluminum wheels should be cleaned and waxed
regularly. Do not use abrasive cleaners, as they could
damage the protective coating.
ALUMINUM WHEEL HUB CAP
Remove or Disconnect
1. Tire and wheel assembly
2. Place a block of wood approximately 2" in
diameter with a squared off end against the back
surface of the cap.
A sharp hammer biow on the
block of wood will
remove the cap.
Install or Connect
1. Place
cap into position at wheel opening and
place a block of wood at least three inches in
diameter against cap face. Install cap by striking
block of wood with hammer.
2. Tire and wheel assembly
NOTICE: Failure to hit cap squarely without the
load distributed evenly could result in permanent
damage to the cap.
ALUMINUM WHEEL POROSITY REPAIR
1. Remove tire and wheel assembly.
2. Locate
leaking areas by inflating tire to 345
kPa
(50 psi) and dipping tire and wheel assembly into
a water bath.
3. Mark
leak areas and remove tire from wheel.
4. Scuff inside surface at leak area with 80 grit
sandpaper and clean area with general purpose
cleaner such as
3M #08984 or equivalent.
5. Apply 1/8" thick layer of adhesive/sealant P/N
1052366 or equivalent to leak area and allow
twelve hours of drying time.
6. Mount tire on wheel, pressurize to 345 kPa (50
psi) and check for leaks.
CAUTION: To avoid serious personal
injury, do not stand over tire when
inflating. Bead may break when bead
snaps over safety hump. Do not
exceed
275 kPa (40 psi) pressure
when inflating any tire if beads are
not seated.
14 275 kPa (40 psi)
pressure will not seat beads, deflate,
relubricate the beads and reinflate.
Overinflation may cause the bead to
break and cause serious personal
injury.
7. Adjust
tire pressure to meet specifications.
8. Balance tire and wheel assembly.
9. Install tire and wheel assembly.
ALUMINUM WHEEL REFINISHING
A protective clear or color coating is applied to
the surface of original equipment cast aluminum
wheels.
A surface degradation condition can begin to
develop if frequent, repeated automatic car wash
cleaning abrades or wears off the factory applied
protective coating. This can happen at some automatic
car wash facilities using aggressive silicon carbide
tipped tire brushes
to clean white walls and tires. Once
the protective coating is
damaged, exposure to caustic
cleaners and/or road salt further causes surface
degradation. The following procedure details how to
strip, clean
and recoat aluminum wheels that are
affected by these conditions.
Required Materials:
A~nchern Alumi Prep #33 - stock
#DX533 or equivalent - cleaning and
conditioning chemical for aluminum.
Amchem Alodine
# 1001 - stock #DXSOT
or equivalent - coating chemical for
aluminum.
Ditzler Delclear Acrylic Urethane Clear
-
stock #DAU-75 or equivalent.
Ditzler Delthane Ultra-Urethane Additive
- stock DXR-80 or equivalent.
Service Procedure:
1. Mark wheel and wheel stud for position on car.
2. Remove tire and wheel assembly from car.
3. Mark location of outboard weights and remove.
4. Wash wheel inside and out with water base all
purpose cleaner. Remove grease and oil with
solvent cleaner.
5. Mask off tire prior to painting.
6. Select and follow the correct procedure,
"Aluminum Damage on Wheel Surface" or
"Clear Coat Damage on Unpainted Wheels".
7. Replace wheel weights with nylon coated
weights.
8. Install tire and wheel assembly on car and tighten
wheel nuts to proper torque.
Accent Color Preparation
1. Sand over painted areas that will not require
recoloring with 400 grit (wet or dry) to promote
adhesion of clear coat.
Aluminum Damage on Wheel Surface
1. Mount tire and wheel on brake lathe and spin
slowly.
2. Sand wheel with backing block or pad by holding
abrasive flat to surface of wheel and moving
slowly back and forth from center to outer edge
to remove damage. Use the following sandpaper
grits in the order listed.
A. Sand with 80 grit
B. Sand with 150 grit
C. Sand with 240 grit
3. Continue with "Recoating Procedure."

4A-2 PROPELLER SHAFT
1. SLIP YOKE 2. BEARING CAPS 3. PROPELLER SHAFT
(SEAMLESS TUBE)
Figure 4A-1 Propeller Shaft
Leak
at front slip 1. Rough outside surface 1. Replace seal if cut by
yoke. (An occasional on
slip yoke. burrs on yoke.
Minor burrs
drop of lubricant can
be smoothed by careful
leaking from splined use
of crocus
cloth or
yoke
is normal and honing
with a fine stone.
requires no attention.) Replace
yoke if outside sur-
face is rough or burred
badly.
2. Defective transmission 2. Replace transmission rear
rear oil seal. oil seal.
3. Bring transmission oil
up to proper level after
correction.
Knock in drive line
1. Worn or damaged 1. Replace.
clunking noise when car universal
joints.
is operated under float 2. Side gear hub counter- 2. Replace differential case
condition at
10 mph in bore
in differential and/or side gears as
high gear or "Neutral". worn oversize. required.
Ping, snap, or click in
1. Loose upper or lower 1. Tighten bolts to
drive line. control arm bushing specified torque.
bolts.
2. Worn or damaged 2. Replace.
universal joints.
Scraping noise. Slinger
rubbing on
rear axle carrier. Straighten
slinger to
remove interference.
I
Figure 4A-2 Propeller Shaft Diagnostic Chart 1 I i
NOTICE: Care must be taken not to include COMPANION FLANGE RUN-OUT indicator variation caused by ridges, flat spots or MEASUREMENT other variations in the tube.
Figure 4.4-5
Check companion flange run-out using Tool
4. If runout exceeds specifications, reindex the 5-35819 and 5-8001 Dial Indicator Set or equivalent.
propeller shaft 180" at the rear axle companion Instructions are included with tool. Record run-out
flange and recheck runout. and mark high and low points of companion flange.
A. If companion flange run-out is
O.15mm (.006 in.)
5. If
runout is still over specifications, check rear
or less, remove companion flange balance weight,
axle companion flange for run-out.
if used. No further action is required.

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

REAR AXLE 481-3
1-OUTER BRG. RETAINER
2-WHEEL SEAL
3-WHEEL BRG. CONE
4-WHEEL
BRG. CUP
5-INNER BRG. RETAINER
6-AXLE SHAFT
7-COMPANION FLANGE
8 -PINION OIL SEAL
9-FRONT PINION BRG. CUP
10-FRONT PINION BRG. CONE
1 1-COLLAPSIBLE SPACER
12-PINION NUT
13-DIFFERENTIAL
BRG. CAPS
14-DIFFERENTIAL CAP BOLTS
15-FILLER PLUG
16-REAR COVER BOLTS 17-LUBRICATION
TAG
&
IDENTI FlCATlON TAG
18-REAR COVER
19-REAR COVER GASKET
20-REAR PINION BRG. CUP
21-REAR PlNlON BRG. CONE
22-PINION POSITION
SHIM 23-HYPOID PlNlON
24-DIFF. BRG. SHIM
25-DIFF.
BRG. CUP
26-DIFF. BRG. CONE
27-DIFFERENTIAL ASSY
28-BRAKE BACKING PLATE
29-RING GEAR BOLTS
30-HYPOID
RING GEAR
31-CARRIER &TUBE ASSY
32-WHEEL BOLTS
Fig.
1 Standard Rear Axle

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.

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.