Correcting Non-Uniform Tires - GMC Chevrolet Camaro 1998 Service Manual

0-70 Vibration Diagnosis and Correction
Wheel Stud (Stud Circle) Runout
Use the following procedure whenever the off-vehicle
radial runout and the on-vehicle radial runout are
significantly different, and· earlier attempts to correct
the tire and wheel vibration condition have not
b.een successful.
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1 . Position the dial indicator in order to contact the
wheel mounting studs.
Measure the stud runout as close to the flange as
possible .
. 2. Turn the hub to register on each of the studs.
3. Zero the dial indicator on the lowest stud.
4. Rotate the hub again and check the total amount
of runout.
Specification (Guideline)
Runout tolerance: 0.80 mm (0.030 in)
General Information
Correcting Non-Uniform Tires
Use the following two methods to correct tires which
cause a vibration, although the tires are balanced
properly:
1. This method uses an automatic machine that
loads the tire and buffs small amounts of rubber
from high spots on the outer two tread rows.
• Using this method in order to correct the tires
is usually permanent. This method does not
significantly affect the appearance or the tire
tread life.
• Do not true the tires with a blade-type machine.
This reduces the tread life substantially, and
this often does not permanently correct
the problem.
2. The second method is to dismount the tire and
rotate it 180 degrees on the rim. It is important
that this is be done on the tire and wheel
assemblies which are known to be causing a
vibration, as it is just as likely to cause good
assemblies to vibrate.
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