Front Suspension; Except H Series; H Series - Pontiac TRANS AM 1977 Service Manual

FRONT SUSPENSION 3C-1
FRONT SUSPENSION
The following caution applies to one or more steps in the assembly procedure of components in this portion of the manual
as indicated at appropriate locations by the terminology "See Caution on page 1 of this Section".
C A UT I 0 N: This fastener is an important attaching part in that it
could affect the performance of vital components and systems, and/or
could result in major repair expense. It 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 this part.
CONTENTS OF THIS SECTION
General Description
Except H
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3C- 1
H Series
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3C- 1
Maintenance & Adjustments
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3C-3
Service Procedures
Except H Series
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3C-3
H Series
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3C- 13
Specifications.
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3C-2 1
GENERAL DESCRIPTION
EXCEPT H SERIES
The front suspension (Fig. 3C-1) is designed to allow
each wheel to compensate for changes in the road surface
level without appreciably affecting the opposite wheel. Each
wheel is independently connected to the frame by a steering
knuckle, ball joint assemblies, and upper and lower control
arms. The control arms are specifically designed and
positioned to allow the steering knuckles to move in a
prescribed three dimensional arc. The front wheels are held
in proper relationship to each other by tow tie rods which
are connected to steering arms on the knuckles and to an
intermediate rod.
Coil chassis springs are mounted between the spring
housings on the frame and the lower control arms. Ride
control is provided by double, direct acting shock absorbers
mounted inside the coil springs and attached to the lower
control arms by bolts and nuts. The upper portion of each
shock absorber extends through the spring housing and is
secured with two grommets, two grommet retainers, and a
nut.
Side roll of the front suspension is controlled by a spring
steel stabilier shaft. It is mounted in rubber bushings which
are held to the frame side rails by brackets. The ends of the
stabilizer are connected to the lower control arms. Rubber
grommets at these connections provide flexibility and ride
features.
The upper control arm is attached to a cross shaft
through isolating rubber bushings. The cross shaft, in turn,
is bolted to frame brackets.
A ball joint assembly is riveted to the outer end of the
upper arm. It is pre-loaded by a rubber spring to insure proper
seating of the ball in the socket. The upper ball joint is
attached to the steering knuckle by a castellated nut.
The inner ends of the lower control arm have pressed-in
bushings. Bolts, passing through the bushings, attach the arm
to the frame.
The lower ball joint assembly is a press fit in the arm
and attaches to the steering knuckle with a castellated nut
that is retained with a cotter pin.
Rubber grease seals are provided at ball socket
assemblies to keep dirt and moisture from entering the joint
and damaging bearing surfaces.
GENERAL DESCRIPTION
H SERIES
The front suspension is of the A frame type with short
and long control arms. (Fig. 3C-2) The upper control arm
is bolted to the front end sheet metal at each inner pivot point.
Rubber bushings are used for mounting.
The lower control arm attaches to the front end sheet
metal, with two cam type bolts, through rubber bushings. The
cam bolts adjust camber and caster. The front cam bolts
adjust camber and the rear cam bolts adjust caster.
The upper ball joint is riveted to the upper control arm
and the lower ball joint is pressed into the lower control arm.
The coil springs are mounted between the lower control
arms and the shock absorber tower. The lower control arm
and the shock absorber tower have helical spring seats which
makes spring indexing easy since there is a stop on both seats.