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.
- Support the vehicle on a hoist or jackstands. Support the axle(s)
at curb height. Refer to 
Lifting and Jacking the Vehicle 
 in General Information.
- Turn the ignition ON.
- Place the transmission in NEUTRAL.
- Remove the rear tire/wheel assemblies. Refer to 
Tire and Wheel Removal and Installation 
in Tires and Wheels.
- Remove the brake rotors. Refer to 
Front Brake Rotor Replacement 
or 
Rear Brake Rotor Replacement 
 in Disc Brakes.
- 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.
- Start the vehicle.
- Place the transmission in the highest forward gear.
- 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.
- If a vibration is present, note the J 38792-A 
 reading during acceleration or deceleration.
- Note as to whether or not the pinion nose vibrates under load
during the acceleration or deceleration.
- 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.
- If the vibration is still not reproduced, lightly apply the brakes
to further load the system while maintaining the vibration concern speed.
- 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.