Important: If you have not completed the Vibration Analysis tables as indicated and reviewed Diagnostic Aids, refer to Vibration Diagnostic Aids BEFORE operation.

If the vibration concern has been duplicated but difficult to balance relative component or isolate this component, refer to the following information:

Most vibration concerns are corrected or eliminated by the following methods: correcting excessive runout of a component, correcting of component balance or isolating the component which has abnormal contact with other object/component.

Components which can generate lots of energy and are experiencing excessive runout, imbalance or ground-out conditions can produce a vibration with a strong enough amplitude that the vibration can transmit to components which are closely related. This condition is usually related to and sensitive to torque-load. The most likely system that could exhibit this condition is the driveline.

If a drive axle differential that has internal component condition such as excessive runout, misalignment, imbalance, etc., that could produce vibration concerns which may be transmitted into the drive shaft. This kind of vibration occurrence can increase or decrease in severity based primarily upon torque-load, but can also be affected by cold or hot conditions.

The drive shaft and other relative components may or may not pass inspections for wear or damage, runout, alignment, etc., depending upon whether there is only one vibration source or more.

If the Vibration Analysis - Driveline table instructed you to system balance the driveline and you experienced difficulty in CAREFULLY following the procedures indicated - the EVA strobe readings seem to keep changing all the time, then the axle differential attached to the drive shaft should be suspected to have internal problems, and vibration resulted from the problems is being transmitted to the drive shaft. Refer to Diagnostic Starting Point - Rear Drive Axle, for internal axle diagnostics.