Tools Required

J 23498-A Driveshaft Inclinometer

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. Raise and support the vehicle. Ensure that the drive axle is supported at ride height - vehicle body supported by suspension components - with the wheels free to rotate. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place the transmission in NEUTRAL.
3. Clean any corrosion or foreign material from the U-joint bearing caps.
4. Remove any of the U-joint bearing cap snap rings that may interfere with the correct placement of the J 23498-A .



5. Inspect the rear propeller shaft for proper phasing.

5.1.	Rotate the propeller shafts to align the rear shaft flanges vertically.

5.2.	Install the J 23498-A to the lower U-joint bearing cap of the rear U-joint of the rear propeller shaft. The J 23498-A should be aligned perpendicular to the propeller shaft.

5.3.	Set the indicator line on the J 23498-A to 15, the horizontal reference.

5.4.	Rotate the propeller shaft slightly to center the bubble to the indicator. The U-joint is now vertical.

5.5.	Without disturbing the setting on the J 23498-A , remove the J 23498-A from the rear U-joint bearing cap.

5.6.	Install the J 23498-A to the lower U-joint bearing cap of the front U-joint of the rear propeller shaft.

5.7.	Observe the reading of the front U-joint with the J 23498-A still set to 15, the horizontal reference.

6. If the difference between the rear propeller shaft rear U-joint and the splined yoke U-joint is 1.5 degrees or less, the propeller shaft and the splined yoke are properly phased to each other.
7. If the difference between the rear propeller shaft rear U-joint and the splined yoke U-joint is greater than 1.5 degrees, the propeller shaft and the splined yoke are not aligned properly to each other at the stub shaft, constructed improperly, or damaged from twisting.

•	If the stub shaft is keyed to ensure properly alignment of the rear shaft and the splined yoke, then the propeller shaft requires replacement to restore proper cancellation of the U-joints.

•	If the splined shaft is not keyed, attempt to re-align the rear shaft and splined yoke to each other. Repeat this inspection procedure to confirm the results. If proper phasing cannot be obtained, then the propeller shaft requires replacement to restore proper cancellation of the U-joints.