1988 PONTIAC FIERO Service Repair Manual

3C-6 FRONT SUSPENSION
Ball Jo~nt-Replacement
1 Raise car, support w~th floor stands under frame
2 Remove tlre and wheel assembly.
3. Place floor jack under control arm sprtng seat
CAUTION Floor jack must
remaln under control arm sprbng seat dur~ng removal and tnstallat~on to retam sprlng and control arm In posttlon.
4 Remove cotter ptn, and loosen castellated nut Use J 24292A to break ball jolnt loose from knuckle Re
move tool, and separate jolnt from knuckle
5 Gu~de lower control arm out of openlng In splash sh~eld w~th a putty kntfc or stmtlar tool
6 Remove grease fttt~ngs, and ~nstall tools as shown below.
Press ball jolnt out of lower control arm
Inspection-Steering Knuckle
Installation
See NOTICE on Page 3C.1 of this section.
1. Position ball joint into lower control arm and press in
until it bottoms on the control arm, using tools as
illustrated below.
Grease purge on seal must be located facing inboard.
2. Place ball joint stud in steering knuckte.
3. Torque ball stud nut to 120
Nm (90 Ib. ft.). Then
tighten an additional amount enough to align slot in
nut with hole in stud. Install cotter pin.
4, Install and lubrtcate ball joint fitting until grease appears
at the seal.
5. Install tire and wheel assembly.
6. Check front alignment as described in Section 3A. Reset as requrred. Lower car.
Inspect the tapered hole
In the stcerlng knuckle Remove
any dtrt. If out.of-roundness, defor:nat~on or damage IS noted, the knuckle MUST be replaced
Inspection-Ball Joint
Ball
jo~nt seals should be carefully inspected for cuts
and tears. Whenever cuts or tears are found, the ball joint
MUST be replaced.
REMOVING BALL JOINT
INSTALLING BALL JOINT
LOWER CONTRCL ARM
FI~ 606 Remov~ng and Installing Ball Joint

FRONT SUSPENSION 3C-7
L~urrr Csnwd Armlail Spring-Replmmmt
1. Rrire vehicle using s hoist.
2. Rmwe wheel md tire.
3. Rmwe staMlizar link md krdrinm at L.C.A. 1. Rmwe pivot bdt nuts. DO NOT remove
pivot bdU at this time. 5. Instal 5-23028 drptor to jjrck and pljrce into paition with 5.23028 urpporting krdrinw. 6. Install jrckstcmd undsr wUi& frme rail on oppolite side of vehicle. 7. RrJre 5-a028 enough to remwe both pivot bolts. 8. Lowr 5-23028 crretully, rr drown below. 9. Rmove wring and insulator te inruleto! to spring.
10. Rmwe ball joint from knuckle using 5-24292A as wllined erdier. 11. Rqlrce $uhin@ in L.C.A. 12. Install prm in wane order of removal.
FRONT CROSSMEMBER
SPRING TO BE INSTALLED
WlTH TAPE AT
LOWEST POSITION'BOTTOM OF SPRING IS
COILED HELICAL, AND THE TOP IS COILED
FLAT
WlTH A GRIPPER NOTCH NEAR END
OF WIRE.
LOWER CONTROL
AFTER ASSEMBLY, END OF SPRING
ARM COIL MUST COVER ALL OR PART OF
ONE INSPECTION DRAIN HOLE. THE
OTHER HOLE MUST BE PARTLY
EXPOSED OR COMPLETELY UNCOVERED.
FRONT
CROSSMEMBER

BOLT MUST BE INSTALLED
DIRECTION SHOWN.
INSTALL THE FRONT LEG
OF THE LOWER
CONTROL ARM INTO THE CROSSMEMBER
PRIOR TO INSTALLING THE REAR LEG.
CONTROL ARM MUST BE POSITIONED
TO
"2" CURB HEIGHT DIMENSION
WHEN BOLTS ARE TORQUED.
520087-3C
Fig. 607 Removing and Installing Coil Spring/LCA

3C-8 FRONT SUSPENSION
REMOVING FRONT BUSHING
I -----------------------~-~~ddddddddddddd-~----~~-~--~--~ I
INSTALLING FRONT BUSHING I I INSTALLING REAR BUSHINGS
............................
FLAWING FRONT BUSHING
I I
I
I I I I I I I 1 520088-3C

FRONT SUSPENSION 3C
KNUCKLE, HUBAND-DISC-REPLACEMENT
1. Siphon master cylinder.
2. Raise vehicle. 3. Remove wheel-and-tire. 4. Remove brake hose from strut. 5. Remove caliper support safely. 6. Remove huband-disc. 7. Remove splash shield. 8. Disconnect tie rod from knuckle. 9. Support lower control arm. 10. Disconnect ball joint from knuckle,
using J-24292A. 11. Remove two bolts attaching strut to
knuckle, and remove knuckle.
12. Reverse order of removal to install.
CROSSMEMBE R
LOWER CONTROL
ARM
COTTER PIN
120 N.m maximum hand torque NUT
Permissible to align cotter
pin slot
(1/6 turn max). do not back off nut for
cotter pln insert~on.
520089-3C
Fig. 609 Removing and Installing Knuckle

3C-18 FRONT SUSPENSION
1-SIDE RAIL
2-CROSSMEMBER 3-WASH E
R
4-BOLT (105 Nwm)
5-LOCATING PIN
I I Fig. 6 10 Front Suspension Crossmember
SPEGIFICA"T0NS
Strut Aarembly Stmt-to-Knuckle Bolts
Strut-to-Upper Mount Nut
Upper Mount-to-Wheelhouse Tower
Lower Contrd Arm
Pivot
Rolt Nuts
Bumper-to-LCA
LCA Ball Joint-to-Knuckle
Knuckle Strut-to-Knuckle Bolts
LCA Ball Joint-to-Knuckle
Ft. Lbs.
Fig.
6 1 1 Specifications

REAR SUSPENSION 30.1
SECTION 3D
REAR SUSPENS
NOTICE: All rear suspension fasteners are important attaching parts in that they could affect the
performance of vital parts 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 all parts. There is to be no welding as it may result in extensive damage and weakening
of the metal.
CONTENTS
General Information ................................ 3D- 1 Rear Lower Control Arm ............................ 3D-4
Qn-Car Service ............................ .. .......... 3D- 1 Bushing (Rear Lower Control Arm) ........... 3D-4
Shock Absorbers ........................................ 3D- 1 Torque Arm .............................................. 3D-5
Coil Springs and Insulators ......................... 3D- 1 Rear Stabilizer Shaft .................................. 3D-6
Track Bar ................................................... 3D-3 Bumper (Rubber) ....................................... 3D-6
Track Bar Brace ................... .. ................. 3D-3 Torque Specifications .................................. 3D-9
GENERAL INFORMATION
The rear axle assembly is attached to the vehicle
through a link type suspension system. The axle
housing is connected to the body by two lower control
arms and a track bar. A single torque arm is used in
place of upper control arms. It is rigidly mounted to the
rear axle housing at the rear and through a rubber
bushing to the transmission at the front. Coil springs
are used to support the weight of the car, and ride
control is provided by shock absorbers mounted to the
rear of the axle housing. A stabilizer shaft is optional.
The shock absorbers are mounted at the bottom
with a bolt and nut to brackets welded to the axle
housing, and at the top to the reinforced body area with
a nut. The only service the shock absorbers require is
replacement if they
have lost tllcir resistance, are
danaged, or are leaking flldd.
ON-CAR SERVICE
SI-IOCK ABSORBERS
Fig. 602
Remove or Disconnect
1. Hoist car and support rear axle.
2. From above, pull back carpeting and remove
shock absorber upper mounting nut.
NOTICE: Axle assembly must be supported
before removing upper shock absorber nut to avoid
possible damage to brake lines, track bar and prop
shaft.
3. Loosen and remove shock absorber lower
mounting nut from shock absorber. Remove
shock.
Install or Connect
NOTICE: See NOTICE on Page 3D-1 of this
section.
1. Position shock absorber through body mounting
hole and loosely install the lower shock absorber
mounting nut.
2. From above, install the upper shock absorber
retainer and nut. Torque nut.
3. Torque lower shock absorber nut.
4. Remove rear axle support and lower car.
COIL SPRINGS AND INSULATORS
Fig. 603
Remove or Disconnect
1. Hoist car on non twin post-type hoist and support
rear axle assembly with an adjustable lifting
device.
2. Track bar mounting bolt at axle assembly.
Loosen track bar bolt at body brace.
3. Rear brake hose clip at underbody to allow
additional axle drop.
4. Right and left shock absorber lower attaching
nuts.
5. Carefully lower rear axle and remove spring(s)
and or insulator(s).
NOTICE: DO NOT suspend rear axle by brake
hose. Damage to hose could result.
Install or Connect
NOTICE: See NOTICE on Page 3D-1 of this
section.

3D-2 REAR SUSPENSION
1. RAIL
2. JOUNCE BUMPER
3. SPRING INSULATOR ASSEMBLY
4, COIL SPRING
5. OPTIONAL STABILIZER BAR
6. LOWER CONTROL ARM
7. UNDERBODY
8. TORQUE ARM
9. PROP SHAFT
10. SHOCK ABSORBER
11. TRACK BAR
12. TRACK BAR BRACE
Fig.
60 1 Rear Axle and Suspension Assembly

REAR SUSPENSION 30-3
1. Position springs and insulators in spring seats and
raise rear axle until rear axle supports weight of
vehicle at normal curb height position.
2. Shocks to rear axle. Torque nuts. 1-17 N.M (13 FT.LB.1 3. Thoroughly clean track bar-to-axle assembly bolt
2-UNDERBODY and nut as outlined under Recommendation for
Reuse of Prevailing Torque Fasteners in Section
3-95 NeM (70 FT.LB.) 4. Track bar mounting bolt at axle and torque nut.
4-AXLE ASM. Torque track bar to body bracket nut.
5. Brake line clip to underbody.
6. Remove adjustable lifting device from beneath
axle and lower car.
TYPICAL SHOCK INSTALLATION TRACK BAR (RH SHOWN)
Remove or Disconnect
at body bracket.
3. Track bar.
Install or Connect
NOTICE: See NOTICE on Page 3D-1 of this
1. Position track bar in body bracket and loosely
install bolt and nut.
2. Thoroughly clean track bar to axle assembly bolt
and nut as outlined under Recommendations for
Reuse of Prevailing Torque Fasteners in Section
3. Position track bar at axle. Install bolt and nut.
4. Torque track bar nut at body bracket to 78 Nem
5. Remove rear axle support and lower car.
TRACK BAR BRACE
1. Hoist car and support rear axle.
2. Heat shield screws from track bar brace.
3. Three track bar brace to body brace screws.
4. Nut and bolt at body bracket. Remove track bar 1-REAR UNDERBODY SHOCK TOWER
AND SPRING SEAT.
2-SPRING INSULATOR
NOTICE: See NOTICE on Page 3D-1 of this 3-COIL SPRING
1. Position track bar brace and loosely install nut Fig. 603 Coil Springs and Insulator and bolt at body bracket.
2. Position other end of track bar brace at body
bracket. Install three screws and torque screws.
3. Torque track bar nut at body brace.