GMC Chevrolet Camaro 1998 Service Manual page 90

0· 78 Vibration Diagnosis and . Correction
182137
General Information
The propeller shaft is not balanced if one of the
following conditions exist:
• The weight and the original light spot are at the
6 o'clock position.
The above condition means that there is not
enough weight on the propeller shaft. In order to
correct the balance, add a second weight next
to the first weight. Inspect the balance again using
the strobe light.
If the weights are now between 90 and
180 degrees off (between the 9 and the
3 o'clock positions) too much weight exists. In
order to correct the balance, split the two weights
equally on either side of the original light spot
in order to produce a total weight between
one and two weights (between O and 120 degrees
apart). Inspect the balance again using the
strobe light. Adjust the weights as necessary.
• The weight and original light spot are
90 to 180 degrees off (between the 9 and the
3 o'clock positions).
The above condition means that one weight is too
much. In order to correct the balance, split the
two weights equally on either side of the original
light spot in order to produce a total weight
less than one (between ·~ 20 and 180 degrees
apart). Inspect the balance again using the strobe
light. Adjust the weights as necessary.
• The weight and the original light spot are
within 180 degrees of the 6 o'clock position.
Move weight towards the 6 o'clock position.
Inspect the balance again using the strobe light.
Adjust the weight as necessary. Refer to the
previous two conditions.
If the shaft will not balance using two weights, then
place a third weight on the light spot. Split the first two
weights in order to produce a total weight between
two and three weights.
If three weights fail to balance the driveline, then
replace the propeller shaft.
When the propeller shaft balances, road test the
vehicle in order to verify that the vibration is eliminated.
Driveline System Balance without the
Electronic Vibration Analyzer
The following procedure is designed to fine-tune the
balance of the propeller shaft while it is mounted in the
vehicle. The procedure also is able correct residual
imbalance of the remaining driveline components.
Prior to balancing the driveline system, verify that the
propeller shaft and the pinion flange runout are
within specification.
Do not overheat the engine when performing this
procedure.
(
1. Raise the vehicle to curb height. Support the
vehicle on a hoist or on safety stands. Do not
allow the axle to hang. Refer to Lifting and Jacking
(
the Vehicle
2. Remove the rear tire/wheel assemblies. Refer to
Wheel Removal