Front Wheel Bearings - Pontiac FIREBIRD 1972 Service Manual

3-16
1972 PONTIAC SERVICE MANUAL
I
WARNING: THlS KEEPS SPRING COM-
PRESSED.
I
2. Remove hub and backing plate assembly or brake
caliper assembly [see STEERING KNUCKLE (A,
G & X Series)
-
REMOVE steps 2 through 51.
3. Remove lower ball joint stud from steering knuckle
by prying on control arm using a suitable pry bar and
tapping sharply on knuckle in area of ball stud.
NOTE: Instead of using a pry bar, the PRE-
FERRED METHOD using tool JZ374Z- l can
be used (Fig. 3-23).
4. Install ball joint retaining nut on ball stud. Using a
socket and torque wrench, measure amount of torque
required to turn the ball.stud in its socket.
CAUTION: I f any torque is required to rotate
the ball stud, indications are that the ball joint
is in a satisfactory condition. I f zero torque is
observed, suficient wear has taken place and
the baU joint should be replaced. In instances
where a torque wrench is not available the ball
joint can be satisfactorily checked by attempt-
ing to rotate the stud by hand. Some resistance
should always be present.
LOWER BALL JOINT
-
A, G & X SERIES
The lower ball joint used on all A, G & X Series is a
tension type joint. This type of ball joint is designed so that
the coil suspension spring pressure is always keeping the
ball stud, inside the ball joint, firmly in its seat. With this
type ball joint, looseness will not normally be present. The
accurate method for checking wear in this type ball joint
is given below:
1. Raise car and support front lower control arm under
spring seat.
WARNING: THlS KEEPS SPRING COM-
PRESSED.
2. Remove lubrication fitting from the ball joint.
3. Remove hub and backing plate assembly or brake
caliper assembly [see STEERING KNUCKLE (A,
G & X Series)
-
REMOVE steps 2 through
5
1.
4. Remove lower ball joint stud from steering knuckle
by prying on control arm using a suitable pry bar and
tapping sharply on knuckle in area of ball stud.
NOTE: Instead of using a pry bar, the PRE-
FERRED METHOD using tool J23742- 1 can
be used (Fig. 3-23).
Mount a dial indicator, using a "C" clamp and exten-
sion on lower control arm.
Position plunger of dial indicator into lubrication fit-
ting hole so that plunger is touching base of ball stud
inside ball joint.
Tighten all connections of the dial indicator mount-
ing and set indicator to zero.
Grasp threaded portion of ball stud and pull straight
up and down, noting reading of dial indicator. Repeat
this step several times to get a stable average reading.
If reading is over .050n, the ball joint must be re-
placed.
GENERAL INFORMATION
Periodic service of the suspension system consists of regu-
lar lubrication as outlined in Section 0. Never attempt to
straighten a bent part, replace it with a new part.
Lubrication fittings are provided at the front suspension
ball joints. Shock absorbers do not require lubrication and,
in case of leaks or malfunction, they should be replaced.
Periodically it may be necessary to make certain adjust-
ments and checks of the suspension system to maintain
desirable handling and steering characteristics and mini-
mize tire wear. These checks are: front wheel bearings,
wheel and tire balance, wheel and tire lateral run-out,
upper and lower control arm spherical ball joints, chassis
springs, shock absorbers, and wheel alignment. They are
made with the parts on the car.
FRONT WHEEL BEARINGS
CHECK ADJUSTMENT
NOTE: Tapered roller bearings are used on all
series and they have a slightly loose
feel
when
properly adjusted. This differs from ball bear-
ings which may be pre-loaded without adverse
effect.
A
design feature of front wheel taper
roller bearings is that they must never be ire-
loaded. Damage can result by the steady thrust
on roller ends which comes from pre-loading
(Figs. 3- 13, 3- 14 and 3- 15).
1. ~ i i s e car and support at front lower control arm.
2. Spin wheel to check for unusual noise.
3. If bearings are noisy or excessively loose, they should
be cleaned and inspected prior to adjustment.