Vibration in Service-Stall Test (Torque Sensitive)

Vibration in Service-Stall Test (Torque Sensitive)

Special Tools

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

For equivalent regional tools, refer to Special Tools and Equipment Vibration Diagnosis and Correction.

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 Service and Repair.

4. Remove the tire and wheel assemblies from the vehicle. Refer to Tire and Wheel Removal and Installation Service and Repair.

5. Remove the brake rotors or drums, if equipped, from the drive axle or axles.

6. Hold the vibration sensor of the EL-38792-A - Electronic Vibration Analyzer (EVA) 2, against the pinion nose.

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 vehicle.

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. If a vibration is present, note the EL-38792-A - EVA 2 reading during acceleration or deceleration.

11. Note as to whether or not the pinion nose vibrates under load during acceleration or deceleration.

12. If the vibration is not reproduced, reinstall the brake rotors and/or drums and the wheel/tire assemblies to put an additional load on the system. Perform steps 7-11 and check the components again.

13. If the vibration is still not reproduced with rotors and/or drums reinstalled, lightly apply the brakes to further load the system while maintaining the vibration concern speed.

14. If the pinion nose vibrates under acceleration or deceleration, and other driveline components have been eliminated as a cause, the vibration may be an internal axle problem.