GMC Chevrolet Camaro 1998 Service Manual page 81

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General Information
The most effective way to minimize the possibility of
force variation as a factor in tire and wheel assembly
vibrations is to ensure that the tire and wheel
assembly runout is at an absolute minimum. However,
some tire and wheel assemblies exhibit
vibration-causing force variation even though they are
within runout and balance tolerances. These
instances are becoming rare due to tighter tolerances
and higher standards in manufacturing.
The following two alternatives are available if force
variation is suspected as a factor in tire and wheel
assembly vibration complaints:
• Buff the tires.
• Substitute one or more known good tire and
wheel assemblies.
The tires may be buffed on a tire matching machine
that is designed to remove small amounts of
rubber from the outer rows of the tread blocks at the
location of the stiff spots under load. This eliminates
the spindle deflection. This type of equipment is
not currently in widespread use. Do not use a TRUER
or any tool that is designed to make the tire perfectly
round. These tools will not correct the condition.
You may substitute one or more known good tire and
wheel assemblies when a tire manufacturer is not
available locally.
Lateral Force Variation
255806
Lateral force variation tends to deflect the vehicle
sideway, or laterally. Lateral force variation is based
on the same concept as radial force variation. A
SNAKY belt inside the tire may be the cause of lateral
force. The tire substitution method may have to be
used before tire replacement.
Vibration Diagnosis and Correction 0-69
A lateral force variation condition is rare. The best way
to eliminate lateral force variation as a factor in tire
and wheel vibration conditioni;; is to ensure that
the lateral runout of the tire and wheel assemblies is
at an absolute minimum.
The vehicle will WOBBLE or WADDLE at slow speeds
of 8-40 km/h
(5-25
mph) when lateral force variation
is excessive. This condition is usually related to
the first-order of tire and wheel rotation.
Wheel Hub/Axle Flange Runout
Inspect the wheel hub/axle flange runout when lateral
runout occurs during on-vehicle testing but not
during off-vehicle testing. The tolerances provided are
only guidelines. Perform corrections only if the
on-vehicle runout cannot be brought to within
tolerance.
1. Position the dial indicator on the machined
surface of the hub, the axle flange, or the
rotor, outside of the wheel studs.
2. Rotate the hub in order to find the low spot.
3. Set the dial indicator to zero at the low spot.
205276
4. Rotate the hub again and check the total amount
of runout.
Specification (Guideline)
Runout tolerance:
0.130
mm
(0.0050
in)