Vibration in Service-Stall Test (Torque Sensitive)

Vibration in Service-Stall Test (Torque Sensitive)

Notice: 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. Support the vehicle on a hoist or jackstands. Support the axle(s) at curb height. Refer to Vehicle Lifting.
2. Turn the ignition ON.
3. Place the transmission in NEUTRAL.
4. Remove the rear tire/wheel assemblies.
5. Remove the brake rotors.
6. Hold the J 38792-A sensor against the pinion nose.

Notice: 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. Start the vehicle.
8. Place the transmission in the highest forward gear.
9. Have an assistant 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 J 38792-A reading during acceleration or deceleration.
11. Note as to whether or not the pinion nose vibrates under load during the acceleration or deceleration.
12. If the vibration is not reproduced, reinstall the brake rotors and the wheel/tire assemblies to put an additional load on the system. Check the components again while an assistant maintains the vehicle at the vibration concern speed.
13. If the vibration is still not reproduced, 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.