Table of Contents
Advertisement
3 E-4
1977 PONTIAC SERVICE M A N U A L
Fig.
3E-4
Wheel Nut Tightening Sequence
should be well lubricated with an approved tire lubricant.
After mounting, inflate to 40 psi so that beads are
completely seated.
WARNING: D O NOT STAND OVER TIRE
WHEN INFLATING. BEAD M A Y BREAK
W H E N BEAD SNAPS OVER SAFETY
H U M P
A N D
CAUSE
SERIOUS
PERSONAL INJURY.
WARNING: D O NOT EXCEED 4 0 PSI
PRESSURE W H E N INFLATING. IF 4 0 PSI
PRESSURE WILL N O T SEAT BEADS,
DEFLATE,
RE-LUBRICATE
A N D
REINFLATE.
OVER
INFLATION M A Y
CAUSE THE BEAD T O BREAK AND
CAUSE SERIOUS PERSONAL INJURY.
Install valve core and inflate to proper pressure. Check
the locating rings of the tire to be sure they show around the
rim flanges on both sides (Fig. 3E-5).
Tire Repair
There are many different materials and techniques on
the market to repair tires. As not all of these work on all types
of tire,
tire
manufacturers have published
detailed
instructions on how and when to repair tires. These
instructions can be obtained from the tire manufacturer.
BALANCING WHEELS
There are two types of wheel and tire balance: static (Fig.
3E-6) and dynamic (Fig. 3E-7). Static balance is the equal
distribution of weight around the wheel. Wheels that are
Fig.
3E-5
Locating Rings
statically unbalanced cause a bouncing action called shake.
This condition will eventually cause uneven tire wear.
Dynamic balance is the equal distribution of weight on
each side of the centerline so that when the tire spins there
is no tendency for the assembly to move from side to side.
Wheels that are dynamically unbalanced may cause shimmy.
General Balance Precautions
Deposits of mud, etc. must be cleaned from the inside
of the rim. 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
recommendation.
Off-Car Balancing
When balancing wheels off the car, use a balancer which
pilots the wheel by the center hole (not the lug holes) if
possible.
Some electronic off-car balancers are more accurate than
the on-car spin balancers, but do not correct drum or rotor
unbalance. If the vibration is off-car balance, an on-car
balance may also be needed. When doing this additional
balance, do not remove the wheel weights from the electronic
off-car balance. Instead, split the new on-car weights equally
between the inner and outer rim flanges (to avoid disturbing
the dynamic balance from the off-car balancer).
On-Car Balancing
Front Wheels
-
Lift front of car with floor jack under
front cross member in center of car to allow car to vibrate
while balancing.
The lower control arm should be supported as far
outboard as possible.
If the above method is not used, front tires should be
balanced on rear positions, or on an off-car balancer.
NOTE: Front wheels should be spun with the engine.
Follow warning (below) 35 mph drive wheel speed limit.
Rear Wheels
-
T o distinguish between standard axle and
anti-spin on passenger cars, raise rear of vehicle so both
wheels are clear of ground. With the transmission in park (in
gear with manual transmission), attempt to turn one wheel
Advertisement
Table of Contents
