1988 PONTIAC FIERO tire type

STEERING LINKAGE 3B6-1
SECTION 3B6
STEERING LINKAGE
The following notice applies to one or more steps in the assembly
procedure of components in this portion of the manual as Notice indicated at
appropriate locations by the terminology "See Caution on Page
1 of this
Section
" .
NOTICE: These fasteners are important attaching parts in that they
could affect the performance of vital components and systems,
andlor could
result in major repair expense. They must be replaced with one of the same
part number or with an equivalent part if replacement becomes necessary. Do
not use a replacement part of lesser quality or substitute design. Torque
values must be used as specified during reassembly to assure proper retention
of these parts. For prevailing torque
nut(s) and bolt(s), refer to the "Reuse of
Prevailing Torque
Nut(s) and Bolt(s)" chart in Section 10.
CONTENTS
General Description ........................................... 3B6- 1 Relay Rod ............................................................ 3B6-3
Maintenance and Adjustments ............................... 3B6- I Idler Arm ............................................................. 3B6-4
On-Car Service ........................................................ 3B6-2 Pitman Arm ......................................................... 3B6-5
Tie Rods .............................................................. 3B6-2 Specifications ........................................................... 3B6-6
GENERAL DESCRIPTION
A parallelogram type steering linkage connects both
steering gear. The right end of the relay rod is supported by
front wheels to the steering gear through the
pitman arm,
the idler arm which pivots on a support attached to the
The right and left tie rods are attached to the steering arms
frame rail. The
pitman arm and idler arm remain parallel to
and to the relay rod by ball studs. The left end of the relay
each other while they move through symmetrical arcs. See
rod is supported by the
pitman arm, which is driven by the Fig. 3B6-2.
MAONTENANCE AND ADJUSTMENTS
CHELKlNC STtLRING LINKAGE WEIR A? VltlItD FROhl ABOVL
POSITION DIAL INDICATOR
-TO CHECK MOVEMENT
AT THIS POINT
FRONT
OF
MOVE WHEEL IN AND OUT AT FRONT AND BACK
Fig. 3B6-1--Checking Linkage Wear
SUSPENSION AND STEERING LINKAGE CHECK
1. Raise car on one side at frame torque box located
directly behind the front wheel so that tire is
approximately one inch off the floor.
2. Position dial indicator as shown in Fig.
3B6- I .,
3. Position steering wheel so that it is in the locked
position.
4. Grasp front wheel as shown in Fig.
3B6- I. With wheels
in straight ahead position, move wheel back and forth
without moving steering wheel. Gage reading should
not exceed 2.74 mm
(. 108 ").
5. If gage reading is not within specifications, a check
should be made of all suspension and linkage gears.
RELAY ROD HEIGHT ADJUSTMENT
The relay rod position can be adjusted at the idler arm
attach men^. It is important for the height adjustment to be
equal from side-to-side. If not adjusted properly, right-hand
turns and left-hand turns could exhibit differell1
characteristics in handling. This is sometimes called
"orbital steer." Refer to Fig.3B6-5 for setting relay rod
height.

TIRES AND WHEELS 3E-1
RES AND WHEELS
NOTICE: All wheel bolt and nut fasteners are important attaching parts in that they could affect the
performance of vital components and systems, and/or could result in major repair expense. They must be replaced
with one of the same part number or with an equivalent part if replacement becomes necessary. Do not use a
replacement part of lesser quality or substitute design. Torque values must be used as specified during reassembly
to assure proper retention of parts.
CONTENTS
Diagnosis ............................................... Section 3 Tire Repair ................................................... 3E-5
General Information .......................... ..... 3E-1 Waddle ........................................................ 3E-5
........ Replacement Tires ....................... ... 3E- 1 Measuring Wheel Runout ............................ 3E-6
P-Metric Tires ...................... .. ................... 3E-2 Spare Tire ...................................................... 3E-6 ................................................ Tire Placard 3E-2 Match Mounting ......................................... 3E-7
.......................................................... Wheels 3E-2 Balancing Tire and Wheel ............................ 3E-7
....................... Maintenance and Adjustments .............. 3E-2 General Balance Precautions 3E-7 ...................................... Wheel Repair .............................................. 3E-2 Off-Car Balancing 3E-8 .............................. Metric Wheel Nuts and Studs .................... .. 3E-3 On-Car Balancing .. ...... 3E-8
......................................... Inflation of Tires ........................................ 3E-3 Wheel Weights 3E-8 .................... Tire Rotation ........................... ...... . 3E-3 Correcting Non-Uniform Tires 3E-8 .......................... Tire Chain Usage ........................................ 3E-4 Aluminum Wheel Cleaning 3E-9 Aluminum Wheel Hub Cap ......................... 3E-9 Service Operations ..................................... 3E-4 Aluminum Wheel Porosity Repair .............. 3E-9 ......................... Wheel Removal .... .......... 3E-4 Aluminum Wheel Refinishing ...................... 3E-9 Tire Mounting and Dismounting ................. 3E-5 Wheel Nut Torque 3E-10 ......................................
GENERAL INFORMATION ~t is recommended that new tires be installed in
pairs on the same axle. If it is necessary to replace only
The tires and are one tire, it should be paired with the tire having the
designed to operate satisfactorily with loads up to and
most tread, to equalize braking traction. including the full rated load capacity when inflated to
Although they may appear different in tread
the recommended inflation pressures.
design, tires built by different manufacturers with
Correct tire pressures, wheel alignment and identical TPC specification numbers, can be
driving techniques have an important influence on tire
intermixed on the same car. life. Heavy cornering, excessive rapid acceleration, and
heavy braking will increase tire wear.
REPLACEMENT TIRES
Fig. 1
A Tire Performance Criteria (TPC) specification
number is molded in the sidewall near the tire size of
all original equipment tires. This specification number
assures that the tire meets
GM's performance
standards for traction, endurance, dimensions, noise,
handling, rolling resistance, and others. Usually, a
specific TPC number is assigned to each tire size.
When replacing tires, only the size, load range,
and construction as originally on the car are
recommended. This can best be accomplished by
replacing with tires of the same TPC specification
number. Use of any other tire size or construction type
may seriously affect ride, handling,
speedometer/odometer calibration, car ground
clearance and tire clearance to the body and chassis.
This does not apply to the spare furnished with the car.
v// TIRE IDENTIFICATION
Fig. 1 Tire Identification

3E.2 TIRES AND WHEELS
P-METRIC SIZED TIRES
Figs. 1 through 4
All GM cars now use P-metric sized tires.
P-metric tires are available in two load ranges,
standard load
(35 psi max) and extra load (41 psi max).
Most passenger car tires are standard load.
Most P-metric tire sizes do not have exact
corresponding alpha-numeric tire sizes. For example,
a
P205/75R15 is not exactly equal in size and load
carrying capacity to an
FR78-15. For this reason,
replacement tires should be of the same TPC
specification number (same size, load range,
construction) as those originally on the car. If P-metric
tires must be replaced with other sizes, a tire dealer
should be consulted. Tire companies can best
recommend the closest match of alpha-numeric to
P-metric sizes within their own tire lines.
The metric term for tire inflation pressure is the
kilopascal
(kPa). Tire pressure may be printed in both
kPa and psi. One psi equals 6.9 kPa.
See the tire placard or Section OB for tire inflation
specifications.
TlRE PLACARD
Fig. 4
The tire placard is permanently located on the
rear
face of the driver's door, and should be referred
to for tire information. The placard lists the maximum
car load, tire size (including spare), and cold inflation
pressure (including spare).
WHEELS
Wheels must be replaced if they are bent, dented,
have excessive lateral or radial
runout, leak air through
welds, have elongated bolt holes, if wheel nuts won't
stay tight, or if they are heavily rusted. Wheels with
excessive
runout may cause objectional vibrations.
Replacement wheels must be equivalent to the
original equipment wheels in load capacity, diameter,
rim width, offset, and mounting configuration.
A
wheel of improper size or type may affect wheel and
bearing life, brake cooling,
speedometer/odometer
calibration, car ground clearance, and tire clearance to
the body and chassis.
Steel wheels can be identified by a two or
three-letter code stamped into the rim near the valve
stem. Aluminum wheels have the code, part number,
and manufacturer
ID cast into their back side.
MAINTENANCE AND ADJUSTMENTS
WHEEL REPAIR
Wheel repairs that use welding, heating, or
peening are not approved. An inner tube is not an
Fig. 2 Metric Tire Size Format
INFLATION PRESSURE CONVERSION CHART (KI LOPASCALS TO PSI)
Fig. 3 Inflation Pressure Conversion
acceptable repair for leaky wheels or tires. Porosity in
aluminum wheels can be repaired, see Aluminum
Wheel Porosity Repair.

3E.4 TIRES AND WHEELS
TIRE CHAIN USAGE
Fig. 6
Due to limited tire-to-body clearance on certain
cars, tire chain usage recommendations have been
published in the Owner's Manual. When chains are to
be used, most current
GM cars require SAE Class "S"
tire chains. These may also be designated as 1100
Series, Type PL tire chains. These chains are specially
designed to limit the "fly off' effect that occurs when
the wheel rotates.
Manufacturers of tire chains have a specific chain
size for each tire size to ensure proper fit when
installed. Therefore, be sure to purchase the correct
chains for the tires on which they are to be used.
Rubber adjusters should not be used to take up slack
or clearance in chains which are loose due to incorrect
size. Always follow the chain manufacturers
installation instructions.
Use of chains may adversely affect car handling.
When using chains:
@ Adjust speed to road conditions
@ Avoid sharp turns
@ Avoid locked-wheel braking
In general, to help prevent chain damage
to your car:
@ Install the chains on the drive tires as tightly as
possible, then tighten them again after driving
1/4 to 1/2 mile (0.4 to
0.8 kilometer). The use of
chains on the non-drive tires is not recommended;
the chains may contact and possibly damage the
car. If you intend to use chains on the non-drive
tires, be sure there is enough clearance.
e Do not exceed 45 mph (70 km/h), or the chain
manufacturer's speed limit, if lower.
@ Drive in a restrained manner and avoid large
bumps, potholes, severe turns and other
maneuvers which could cause the tires to bounce
up and down.
e Follow any other instructions of the chain
manufacturer which do not disagree with the
above.
Additional specific information is
published in the Owner's Manual.
SERVICE OPERATIONS
WHEEL REMOVAL
Fig. 7A
Sometimes wheels can be difficult to remove from
the car due to foreign material or a tight fit between the
wheel center hole and the hub or rotor. These wheels
can be removed without damage as follows:
1. Tighten all wheel nuts on the affected wheel, then
loosen each wheel nut two turns.
2. Lower car onto floor.
3. Rock the car from side to side as hard as possible
using one or more person's body weight to loosen
the wheel, and/or rock the car from
"Drive" to
"Reverse" allowing car to move several feet in
each direction. Apply quick, hard jabs on the
brake pedal to loosen the wheel.
WPE ""P"
1200 SERIES, SAE CUSS ""Up
WPE ""RP"
4800 SERIES, LUG-REINFORCED
Fig. 6 Examples of Passenger Car Tire Chains
4.
Raise the car. Remove the wheel nuts and the
wheel.
Penetrating oil has not been found to be effective
in removing tight wheels, however,
if it is used, it
should be applied sparingly to the wheels center hole
area only.
DO not allow the penetrating oil to get on
the vertical surfaces between the wheel and the drum
(or rotor) because penetrating oil in this area could
cause the wheel to work loose as the car is driven
causing loss of control.
NEVER use heat to loosen a tight wheel because
the application of heat to the wheel can shorten the life
of the wheel, wheel bolts and/or wheel bearings.
Excessive force such as hammering the wheel or
tire can also cause damage and is not recommended.
Slight tapping of the tire side wall, such as with one's
hand or a rubber mallet, is normally acceptable.
Before installing wheels, remove any build up of
corrosion on the wheel mounting surface and brake
drum or rotor mounting surface by scraping and wire
brushing. Installing wheels without good
metal-to-metal contact at the mounting surfaces can
cause wheel nuts to loosen, which can later allow the
wheel to come off causing loss of control.
Wheel nuts must be tightened in sequence and to
proper torque to avoid bending wheel or brake drum
or rotor.
0P"FIONAL 16" WHEEL
Fig. 7
Firebirds equipped with optional 16" cast
aluminum wheels and cast iron brake
drums will

TIRES AND WHEELS 3E-7
STMAWAY SPARE
TEMPORARY USE ONLV
Fig. 11 Stowaway Spare
MATCH MOUNTING
Fig. 12
Tires and wheels are "match-mounted" at the
assembly plant. This means that the radially stiffest
part of the tire, or "high spot", is matched to the
smallest radius or "low spot" of the wheel.
The "high spot" of the tire is originally marked
by a yellow paint mark
or adhesive label on the
outboard sidewall.
The "low spot" of the wheel will be at the location
of the valve stem.
Before dismounting
a tire from its wheel, a line
should be scribed on the tire at the valve
stem to assure
that it is remounted
ill the same poqition.
Replacement tireq and wheels that are of original
equipment quality will have their "high and low spot"
marked in the same manner.
DOT OR LABEL
SPOT I WHEEL TRAMP I
ADD BALANCE WEIGHTS HERE I
I CORRECTIVE WEIGtiYS I
L G33963-3E.AN Fig 13 Stat~c Unbalance Correction
Dynam~c balance 1s the equal distribution of
weight on each side of the centerline so that when the
n\\embly spin there 14 no tendency for it to move from
side to side. Assemblies that are dynamically
unbalanced may cause wheel shimmy.
WHEEL SHlWWUV
ADDBALANCE , WEtGHTS HERE
Fig. 14 Dynamic Unbalance Correction
Fig.
12 Matched Tires and Wheels
General Balance Precautions
BALANCING TIRE AND WHEEL
Figs, 13 and 14
There are two types of tire and wheel balancing,
static and dynamic. Static balance is the equal
distribution of weight around the wheel. Assemblies
that are statically unbalanced cause a bouncing action
called wheel tramp. This condition will eventually
cause uneven tire wear. Deposits
of foreign material must be cleaned from
the inside of the wheel. Stones should be removed from
the tread in order to avoid operator injury during spin
balancing and to obtain a good balance. The tire should
be inspected for any damage, then balanced according
to the equipment manufacturer's recommendations.
Whenever a heavier, solid locking wheel nut is
used to replace a standard nut, it should
be installed

3E-8 TIRES AND WHEELS
nearest the valve stem, and a 1/2 ounce balance weight
should be added 180" opposite the locking nut on the
wheel's inboard side.
When rotating tires, always re-install the locking
nut nearest the tire valve stem so that it remains
opposite the 1/2 ounce balance weight. This procedure
will improve the on-car wheel balance by compensating
for the heavy locking wheel nut.
Off-Car Balancing
Most electronic off-car balancers are more
accurate than the on-car spin balancers. They are easy
to use and give a dynamic (two plane) balance.
Although they do not correct for drum or rotor
unbalance as does on-car spin balancing, this is
overcome by their accuracy (usually to within 1/8
ounce). When balancing off-car, the wheel should
locate on the balancer with a cone through the back
side of the center pilot hole (not by the wheel stud
holes).
On-Car Balancing
When needed, on-car balancing will help correct
vibrations due to brake drum, rotor, and wheel cover
imbalance.
When balancing on car, do not remove the
balance weights from the off-car dynamic balance. If
more than one ounce of additional weight is required,
it should be split between the inner and outer rim
flange.
NOTICE: The driven tire and wheel assemblies
should be spun using the engine. Limit speed as
stated in the following Caution.
CAUTION: Do not spin the drive
wheels faster than
35 mph (55 km/h)
as indicated by the speedometer. This
limit is necessary because the
speedometer indicates only one-half
of the actual wheel speed when one
drive wheel is spinning and the other
drive wheel is stopped. Personal injury
and damage may result from high
speed spinning.
CAUTION: On cars equipped with
limited slip rear axles, do not attempt
to balance a tire on a
drive wheel with
the other drive wheel on the ground.
The car may drive through this wheel
and cause the car to move
unexpectedly, resulting in personal
injury and property damage.
To distinguish between standard rear axle and
limited slip, raise rear of car so both tires are clear of
ground. With the transmission in park (in gear with
manual transmission), attempt to turn one wheel by
hand. If the wheel can be turned, it is a standard rear
axle; if the wheel cannot be turned, it is a limited slip
rear axle. Also, check for Limited Slip
(G80) on Service
Parts Identification label.
Wheel Weights
Fig. 15
If more than 27 grams (1.0 oz.) are needed, the
wheel weights should be split as equal as possible
between the inboard and outboard flanges.
Balancing of' assemblies with factory aluminum
wheels requires the use of special nylon coated clip-on
type wheel weights. These weights are designed to fit
over the thicker rim flange of the aluminum wheel and
should be installed with a plastic tipped hammer.
Adhesive wheel weights are also available. Use
the following procedure to install adhesive wheel
weights.
Adhesive Wheel Weight Installation
1. Clean wheel by sanding to bare aluminum where
wheel weight is to be located.
2. Wipe wheel weight attachment area with a
mixture of half Isopropyl alcohol and half water.
A clean cloth or paper towel niust be used for this
operat ion.
3. Dry the attachment area with hot air. Surface of
wheel should be warm to the touch.
4. The adhesive backing on wheel weights must be
warmed to room temperature.
5. Remove tape from back of weights. Do not touch
the adhesive surface.
6. Apply wheel weight and press on with hand
pressure.
7. Secure wheel weight with a 70-1 10
N (16-25 lb)
force applied with a roller.
CENTERLINE
1 INSIDE FLANGE CLIPBN WEIGHT 4. ADHESIVE WEIGHT - DYNAMIC 5. ADHESIVE WEIGHT -STATIC ONLY 6. MOUNTING FACE
Fig. 15 Aluminum Wheel Weight Placement
CORRECTING NON-UNIFORM TIRES
There are two ways to correct tires which cause
a vibration even though they are properly balanced.
One method uses an automatic machine which loads
the tire and buffs small amounts of rubber from high
spots on the outer two tread rows. Correction by this
method is usually permanent and, if done properly,
does not significantly affect the appearance or tire
tread life. Tire truing with a blade-type
machine is not
recommended as this reduces the tread life
substantially and often does not permanently correct
the problem.

PROPELLER SHAFT 4A-1
PROPELLER SHAFT
NOTICE: The propeller shaft to pinion flange or slip yoke fasteners are important attaching parts in that
they may affect the performance of vital components and systems, which may result in a major repair expense.
They must be replaced with one of the same part number or with an equivalent part, if replacement becomes
necessary. Do not use a replacement part of lesser quality or substitute design. Torque values must be used as
specified during reassembly to assure proper retention of these parts.
CONTENTS
GENERAL DESCRIPTION ........................ 4A-1
DIAGNOSIS ......................... ............ 4A-1
ON-VEHICLE SERVICE ........................... 4A-I
Propeller Shaft Run-Out
....................................... Measurement 4A- 1
Companion Flange Run-Out
Measurement
............................................. 4A-2
........... Universal Joint Angle Measurement 4A-3
............................ Propeller Shaft Balancing 4A-4
.............................................. Propeller Shaft 4A-8
Removal
.................... .. ............................. 4A-8
GENERAL DESCRIPTION
Figure 4A- I
.............................................. Installation 4A-8
UNIT REPAIR ............................................... 4A-9
Universal Joints
...................... ... ............ 4A-9
....................... Nylon Injected Ring Type 4A-9
..... ....................... Disassembly .... 4A-9
.......................................... Assembly 4A-9
......................... External Snap Ring Type 4A- l 1
............. .................... Disassembly .. 4A- 1 1
........................................... Assembly
4A- 1 1
.................... TORQUE SPECIFICATIONS 4A-12
.................................. SPECIAL TOOLS 4A-12
DIAGNOSIS
Figures 4A-2 and 4A-3
Obiectional vibration, roughness, rumble or
boom
can be caused by the input from a number of
shaft. use a One piece propeller systems. The following diagnostic charts provide a
systematic approach to finding the vehicle problem.
A universal joint and splined slip yoke are located at
the transmission end of the propeller shaft, where they are
held in alignment by a bushing in the transmission exten-
sion housing. The slip yoke permits fore and aft move-
ment of the propeller shaft, as the differential assembly
moves up and down. The spline is lubricated internally by
transmission fluid. A seal in the transmission extension
housing prevents fluid leakage and protects the slip yoke
from dust,
dirt, and other harmful material.
A second universal joint is used where the
propeller shaft connects to the rear axle pinion
companion flange.
The universal joints are lubricated for life and
cannot be lubricated while on the vehicle.
If it becomes
necessary to replace a universal joint, the entire
propeller shaft must be removed from the vehicle. Care
should be taken to avoid jamming, bending or
over-angulating of any parts of the assembly.
On vehicles with steel propeller shafts, production
universal joint bearing caps are retained by nylon injected
rings. Aluminum propeller shafts and all service replace-
ment universal joints use snap rings to retain the bearing
caps.
If a vehicle is to be undercoated, the propeller
shaft must be kept completely free of undercoating
material. Undercoating material or any other foreign
material will upset the propeller shaft balance and
produce serious vibration. To
determine whether the propeller shaft is
causing the problem, drive the vehicle through speed
range and note at which vehicle speed the problem is
most pronounced. Shift the transmission into a lower
gear range and drive the vehicle at the same speed as
when problem was most pronounced.
If the problem is still present at the same vehicle
speed, the propeller shaft may be at fault. Refer to the
propeller shaft diagnostic charts.
ON-VEHICLE SERVICE
PROPELLER SHAFT RUN-OUT MEASUREMENT
Figure 4A-4
If a noise or vibration is present at high speed it
might be caused by a bent shaft, or if a shaft has been
damaged through handling or a collision, it may be
checked for straightness as follows:
1. Raise vehicle on a twin post hoist so that the rear
is supported on the rear axle housing with wheels
free to rotate.
2. Mount
a dial indicator on a movable support that
is high enough to permit contact of the indicator
button with the propeller shaft or mount dial
indicator to a magnetic base and attach to a
suitable smooth place on the underbody of the
vehicle. Readings are to be taken at points
indicated, as shown.
3. With transmission in neutral, check for runout by
turning a rear wheel to rotate the propeller shaft.

I
1. PARTIALLY INSERTED BEARING CAP J10020-4A-F I
Figure 4A-20 Partially Inserted eari in^ Cap
needle bearings. One or more of them has
probably been tipped under the end of the
trunnion.
6. As soon as one bearing cap snap ring retainer
groove clears the inside of the yoke, stop pressing
and install snap ring into place.
7. Continue to press until the opposite snap ring can
be installed in place. If difficulty is encountered,
strike the yoke firmly with a hammer to aid in
seating snap rings. This springs the yoke ears
slightly.
8. Assemble the other half of the universal joint in
the same manner.
External Snap Ring Type
Disassembly
Figures 4A- 17 thru 4A- 19
These universal joints are of the extended-life
design and do not require periodic inspection or
lubrication; however, when these joints are
disassembled, repack bearings and lubricate reservoir
at end of trunnions with chassis lubricant. Use care not
to loosen or damage dust seals. If dust seals are loose
or damaged, the entire universal joint must be replaced.
1. Remove snap rings. If snap ring does not readily
snap out of the grooves, tap the end of the bearing
cap lightly to relieve the pressure against the snap
ring.
2. Support the propeller shaft in a horizontal
position in line with the base plate of a press.
Place the universal joint so the lower ear of the
propeller shaft yoke is supported on a
1 1/8"
socket. Place Tool J-9522-3 on the open
horizontal bearing cap and press the lower
bearing cap out of the yoke ear. If the bearing cap
is not completely removed, lift Tool
9-9522-3 and
insert Spacer
J-9522-5 between the seal and
bearing cap being removed, as shown. Complete
the removal of the bearing cap by pressing it out
of the yoke.
3. Rotate the propeller shaft and press the bearing
cap out of the yoke.
PROPELLER SHAFT 4A-11
I I Figure 4A-2 1 Installing Retaining Rings - External Type
I 1. STRIKE TUBE YOKE EAR IN THIS AREA I
Figure 4A-22 Seating Universal Joint Snap Rings
4. Disengage cross from yoke and remove.
Assembly
Figures 4A-20 thru 4A.22
1. Install one (1) bearing cap part way into one side
of the yokes and turn this yoke ear to the bottom.
2. Insert cross into yoke so that the trunnion seats
freely into bearing cap.
3. Install opposite bearing cap part way, making
sure both trunnions are started straight and true
into the bearing caps.
4. Press against opposite bearing caps, working the
cross all of the time to check for free movement
of the trunnions in the bearing caps. If there
seems to be a hang-up, stop pressing and recheck
needle bearings. One or more of them has
probably been tipped under the end of the
trunnion.
5. As soon as one bearing cap snap ring retainer
groove clears the inside of the yoke, stop pressing
and install snap ring into place.