GMC chevrolet camaro 2000 Service Manual page 66

)
General Information
386772
Other pinion flange assemblies have a runout
compensation weight on the face of the deflector. The
pinion flange assemblies that are system balanced
do not use runout compensation weights.
Measuring the runout on a system-balanced
companion flange is very straight-forward. A balanced
flange that is good will have a measured runout
between 0.00-0.38 mm (0.00-0.015 in). If a balanced
flange has more than 0.38 mm (0.015 in) runout,
replace the flange or reindex the flange 180 degrees
on the pinion. If you replace or reindex a balanced
flange, you must system balance the rear axle again.
Correcting Vibration at the Pinion Nose
Most first-order driveline vibrations originate at the
pinion nose end of the driveshaft. Ensure that
the vibrations are at a minimum at this location in
order to achieve acceptable results. Reduce the runout
of the components to a minimum. Balance the
driveline as a system when necessary.
1. Measure the runout of the propeller shaft and
inspect the tolerance.
2. If the tolerance is excessive, mark the position of
the shaft for future reference and rotate the shaft
180 degrees,
3. Reinstall the shaft and reinspect the runout.
Inspect the level of vibration in order to determine
if the vibration is lower or corrected.
4. If the runout is still excessive, or if the vibration is
still present, refer to Measuring Pinion Flange
Runout. Replace the pinion flange or re-index the
flange 180 degrees if the pinion flange runout
exceeds the tolerance.
Remove and reinstall the pinion flange only once
on axles utilizing a.crush type sleeve. Replace
the sleeve with a new sleeve if the sleeve is
crushed. Removing the sleeve requires rem.oval of
the ring and pinion set. Replace flanges with
excessive runout. Regardless of the method used,
measure the pinion flange runout in order to
ensure that the flange is within tolerance.
Vibration Diagnosis and Correction 0-55
5. Reinspect the propeller shaft runout if the vibration
is present after the pinion flange runout is
corrected. If the propeller shaft runout is still
excessive, correct the runout before doing a
driveline system balance. Either replace the shaft
with a shaft that is within tolerance or sublet the
shaft to a reputable independent for straightening
and re-balance. Ensure that the new or rebuilt shaft
is within runout tolerance before continuing.
6. Once the propeller shaft and pinion flange are
within runout tolerances, inspect to see if the
vibration is still present. If the level of the vibration
is still unacceptable, perform a driveline system
balance procedure.
Correcting Vibration at the Transmission
Tailshaft
First-order driveline vibrations that originate at the
transmission end of the propeller shaft are rare. If the
tailshaft of the transmission is vibrating, inspect the
tailshaft housing bushing for wear or damage. A leaky
transmission tailshaft oil seal indicates bushing
problems.
Feel for vibration at the crossmember underneath the
transmission mount. If there is no vibration, the
transmission mount is functioning properly by isolating
the vibration from the structure of the vehicle. The
transmission mount is therefore probably not the cause
of the vibration.
Use the following procedure if you can feel vibration
on the crossmember and the tailshaft bushing,
and if the transmission output is normal:
182281
1. Measure the propeller shaft runout. If the runout is
excessive, replace the shaft with one that has
acceptable runout. Alternatively, sublet the shaft
to a reputable independent service shop in
order to have the shaft rebalanced and the runout
corrected.
2. Test drive the vehicle. If the vibration is still
unacceptable, balance the shaft on the vehicle.
Refer to Rear Driveline System Balance.