Driveline System Balance With Elect Vibration Analyzer (Eva)

In order to pinpoint the source, you must reproduce the vibration in the service stall. Determine which component is vibrating the most using the EVA. Perform the following steps:
1. Support the vehicle on a suitable hoist or on safety stands. Ensure that the rear of the rear axle is at curb height. Do not allow the axle to hang. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove the rear tire/wheel assemblies.
3. Remove and inspect the brake drums.
4. Ensure that the propeller shaft is free of undercoating. Check for dents or damage to the propeller shaft or U-Joint.
5. Start the engine.
6. Place the transmission in gear.
7. Run the engine at the vehicle speed at which the vibration is occurring.

CAUTION: Do not run the vehicle higher than 89 km/h (55 mph). Stay clear of the universal joints and the balance weight area in order to avoid personal injury. Do not run the vehicle on the hoist for extended periods of time. Running the vehicle on the hoist for extended periods of time may cause the engine or the transmission to overheat.
Determine which end of the propeller shaft is vibrating the most. Hold the EVA's sensor against the pinion nose and the transmission tailshaft assembly. The higher the amplitude reading, the greater the vibration.
- If the vehicle has a two-piece propeller shaft, inspect the center support bearing.
- If the transmission tailshaft vibrates, inspect the transmission crossmember under the transmission mount. The vibration should not be present if the mount is functioning correctly.