Tools Required
J 38792-A Electronic
Vibration Analyzer (EVA) 2
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 drive
axle, or axles 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 from the drive axle, or axles. Refer to
Front Brake Rotor Replacement
and/or
Rear Brake Rotor Replacement
in Disc Brakes.
- Inspect the propeller shaft, or shafts. All propeller shafts should
be free of undercoating before continuing.
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 engine.
- 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.
- Record whether the vibration was present, and at what speed.
- If the vibration is present, determine which end of the driveshaft
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 tailshaft housing.
- If the vehicle is equipped with a multiple-piece propeller shaft,
hold the vibration sensor of the J 38792-A
up to the propeller shaft support bearing assembly, or assemblies
to inspect for vibration.
- If the transmission tailshaft housing is vibrating, hold the vibration
sensor of the J 38792-A
up to the transmission crossmember under the transmission mount. If there
is no vibration on the crossmember, then the transmission mount is working
properly.
- Record which end of the driveshaft is vibrating the most, and
how severe the vibration is. The inspection will be a reference by which to
judge future progress.