One-Piece Prop Shaft System

1. Raise the vehicle on a suitable hoist or on safety stands. Ensure that the rear axle is supported at curb height and that the wheels are free to spin. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place the transmission in NEUTRAL.
3. Ensure that the vehicle has a full tank of fuel or the equivalent amount of weight in the rear to simulate a full tank. The weight of 3.8 liters of gasoline (1 gallon) is approximately 2.8 kg (6.2 lb).

Checking Phasing of U-Joint




Inspect the propeller shaft for correct phasing. Correct phasing means that the front and the rear U-Joint are directly in line or parallel with each other so that proper cancellation takes place




1. Rotate the propeller shaft so that the propeller shaft rear U-joint bearing cap is vertical.
2. Ensure that the front bearing cap is also vertical.
3. Place the inclinometer on the propeller shaft rear U-joint bearing cap in order to ensure that both U-joints are vertical.
4. Set the indicator line above the sight glass on 15 (the horizontal reference). Rotate the propeller shaft until the bubble centers in the sight glass. This action brings the rear U-joint to vertical.
5. Remove the inclinometer without disturbing the setting. Leave the setting on 15.
6. Install the inclinometer on the front U-joint. The bubble should remain centered plus or minus 3 degrees if the shaft is properly phased.

The out of phasing of the single-piece propeller shaft is very unusual. If the shaft is visibly out of place, the end yokes are welded on in the wrong position or the shaft is damaged due to twisting. In either case, replace the propeller shaft before continuing with this procedure.

Measuring the Working Angles
The working angle of a U-joint is the difference between the angles formed when 2 shafts intersect. One piece propeller shaft systems have2 working angles, the front and the rear.
- The 2 working angles should be equal within 1/2 of a degree.
- The working angles should not exceed 4 degrees.
- The working angles should not be equal to 0 because a 0 working angle will cause premature U-joint wear due to lack of rotation of the U-Joint.

Canceled Out Driveline Angles




- The angle formed by the propeller shaft and the rear axle pinion form the rear working angle.
- The angle formed by the propeller shaft and the transmission output shaft form the front working angle.
The angles of these components are most accurately measured from the U-joint bearing caps. Verify that the bearing caps are free of corrosion or foreign material in order to ensure accurate readings. Remove any snap rings that may interfere with the correct placement of the inclinometer. Reinstall the snap rings after you take the measurements.




Obtain the measurements from the same side of the propeller shaft in order to maintain consistent angle measurements (either on the driver side or on the passenger side).
Record the readings on a diagram like the one shown as you proceed through the measurements.

Evaluation
The 2 working angles in a one-piece propeller shaft system should be equal to within 1/2 degree for effective cancellation.