Driveline Vibration Analysis - GMC Chevrolet Camaro 1998 Service Manual

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General Information
Lateral Runout
Legend
(1) Dial Indicator
(2) Tire High Spot
(3) Wheel High Spot
(4) Wheel Low Spot
(5) Tire Low Spot
- - 4
- - 5
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Lateral runout is a sideways variation of the wheel.
This runout causes a twist or a wobble. Measure
lateral runout on a side surface. On the tire and wheel
assembly, measure the side wall of the tire as close
to the tread shoulder design edge as possible.
The gage reads the total runout. The high spot is the
location of the maximum runout. If either flange is
beyond guidelines, replace the rim.
• Aluminum Wheels - 0.762 mm (0.030 in)
• Steel Wheels - 1.143 mm (0.045 in)
Measurement Procedures
Do the following tire and wheel runout measurement:
1. Inflate the tires to specifications.
2. Warm up the tires before taking measurements.
This eliminates flat spotting. You do not need to
warm up newly installed tires.
3. Raise the vehicle on a lift.
If measurement is taken with the wheel off of the
vehicle, mount each tire and wheel assembly
on a dynamic balance machine.
4. Mark the tire and wheel assemblies for exact
replacement.
4.1. Mark a wheel hub bolt. Mark the hub bolt's
exact position on the wheel.
4.2. Mark each tire and wheel assembly for
replacement on the exact hub/rotor
assembly.
Vibration Diagnosis and Correction 0-53
5. Take a radial measurement or a lateral runout
measurement.
5.1. Place the dial indicator in position.
5.2. Rotate the tire and wheel assembly. Or
rotate the wheel in order to find the wheel's
low spot. Adjust the dial indicator to
read zero.
5.3. Rotate the tire and wheel assembly again in
order to verify the low spot location. The
dial indicator must return to zero. Disregard
any dial activity due to welds, paint runs,
or scratches on the wheel.
5.4. Rotate the tire and wheel assembly, or
rotate the wheel. Note the amount of
variance (runout) from zero. Locate the high
spot. Mark the high spot.
6. If there is a large difference in runout
measurements from on-vehicle to off-vehicle,
excessive runout of the bolt circle or the hub may
be causing the problem.
7. If the measured runouts are not within
specifications, vector the tire and wheel assembly
in order to correct the problem.
Driveline Vibration Analysis
The following components are possible sources of
driveline vibration:
• The transmission output shaft
• The propeller shafVs (driveshafVs)
• The union flange
• The pinion gear
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The above components are either bolted or splined
together. Therefore, all of the components rotate at the
same speed, vibrate at the same frequency and
have the same symptoms.