Special Tools

J-38792-A Electronic Vibration Analyzer (EVA) 2

Caution: Do not fill the propeller shaft with foam, oil, or any other substance in order to correct a vibration. Filling the propeller shaft is only effective in reducing an unrelated condition called Torsional Rattle. Filling the propeller shaft should only be done in strict adherence to the procedure outlined in corporate bulletins that address Torsional Rattle. Failure to follow the correct procedure will induce a vibration and/or affect the structural integrity of the propeller shaft. The propeller shaft will then have to be replaced.

1. Turn the ignition ON but do not start the engine.
2. Place the transmission in NEUTRAL.
3. Raise and support the vehicle. Support the drive axle or axles at curb height. Refer to Lifting and Jacking the Vehicle.
4. Remove the tire and wheel assemblies from the vehicle. Refer to Tire and Wheel Removal and Installation.
5. Remove the brake rotors or drums, if equipped, from the drive axle or axles.
6. Inspect the propeller shaft or shafts. All propeller shafts should be free of undercoating before continuing.

Caution: Do not depress the brake pedal with the brake rotors and/or the brake drums removed, or with the brake calipers repositioned away from the brake rotors, or damage to the brake system may result.

7. Have an assistant start the engine.
8. Place the transmission in the highest forward gear.
9. Accelerate and decelerate the vehicle through the speed range at which the vibration was first noted during the Vibration Analysis-Road Testing procedure.
10. Record whether the vibration was present, and at what speed.
11. If the vibration is present, determine which end of the propeller shaft is vibrating the most. Hold the vibration sensor of the J-38792-A Electronic Vibration Analyzer (EVA) 2 , up to the pinion nose and the transmission or transfer case tailshaft housing.
12. If the vehicle is equipped with a multiple-piece propeller shaft, hold the vibration sensor of the J-38792-A EVA 2 up to the propeller shaft support bearing assembly, or assemblies to inspect for vibration.
13. If the transmission or transfer case output shaft housing is vibrating, hold the vibration sensor of the J-38792-A EVA 2 up to the transmission crossmember under the transmission mount. If there is no vibration on the crossmember, then the transmission mount is working properly.
14. Record which end of the propeller shaft is vibrating the most, and how severe the vibration is. The inspection will be a reference by which to judge future progress.