Pontiac FIREBIRD 1972 Service Manual page 1242

WHEELS AND TIRES 10-5
Tire pressure, with tires cold, should be checked monthly
or more often depending on driving habits, and also before
any extended trips. Pressures should be changed, if neces-
sary, to conform to specifications.
NOTE: Maintain 4 to bpsi more in rear than in
front tires of station wagons and hea vi7y loaded
sedans to prevent over-steer and rear ends way.
Under average driving conditions, it is normal for tire
pressure to increase approximately 6 psi due to increased
tire temperature. Check tire pressure with an accurate
gage under cold conditions.
NOTE: High tire pressure may be incurred due
to rapid accelerating and braking, high speeds
or extended trips. This is nonnal under these
conditions, and should not be reduced.
Tire valve caps should always be reinstalled on the valve
(push caps on tire valve extensions). They assist in keeping
air in the tire in case of a valve leak, and keep dust and
water out of the valve.
Higher than recommended inflation pressure can cause:
1. Hard ride.
2. Tire bruising or carcass damage directly under the
tread.
3. Poor traction at rear wheels resulting in uneven wear.
4. Rapid tread wear at center of tire.
Lower inflation pressures than recommended can cause:
1. Tire squeal on turns.
2. Hard steering.
3. Rapid and uneven wear on the edges of tire tread.
4. Tire rim bruises and various types of rupture.
5. Tire cord fatigue or breakage.
6. Tramp and shimmy troubles.
7. High tire temperatures.
8. Car roll when turning a corner or making a sharp
swerve in traffic.
TIRE ROTATION
NOTE: Inspect disc brake linings for wear each
time the tires are rotated. See Section 5E, Lin-
ing Inspection.
Tire noises due to uneven tire wear are often improperly
diagnosed as bearing, wheel or rear axle malfunctions re-
sulting in unnecessary work. To minimize tire noise and
equalize wear, it is recommended that tires be rotated
approximately every 6,000 miles as shown in Fig. 10-5.
This will prevent undue wear on any particular tire which
might cause excessive noise. When rotating tires, do not
neglect the spare since tires deteriorate through disuse.
Wheels and tires should be balanced on car at time of
rotation.
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A '
WITH SPACE
FRONT OF CAR SAVER SPARE
e m - -
Fig. 10-5 Tire Rotation Diagram