Propeller Shaft Phasing Inspection
Special Tools
J-23498-A Driveshaft Inclinometer , or equivalent
Note: This inspection procedure is intended to inspect propeller shaft systems with 2 or 3 U-joints only.
Correct phasing of a propeller shaft refers to the relative alignment of the U-joint yoke flanges to each other to provide proper cancellation of the U-joints. The yokes should be directly aligned to within the range specified in this procedure.
- Raise and support the vehicle. On vehicles with solid axles, ensure that the drive axle is supported at ride height--vehicle body supported by suspension components. Ensure the wheels are free to rotate. Refer to Lifting and Jacking the Vehicle .
- Place the transmission in NEUTRAL.
- Clean any corrosion or foreign material from the U-joint bearing caps.
- Remove any of the U-joint bearing cap circlips that may interfere with the correct placement of the J-23498-A Driveshaft Inclinometer , or equivalent.
- Inspect the prop shaft for proper phasing.
5.1. | Rotate the prop shaft or shafts to align the shaft yoke flanges vertically. |
5.2. | Install the J-23498-A Driveshaft Inclinometer , or equivalent to the lower U-joint bearing cap of the rear U-joint of the shaft. The J-23498-A Driveshaft Inclinometer , or equivalent should be aligned perpendicular to the propeller shaft. |
5.3. | Set the indicator line on the J-23498-A Driveshaft Inclinometer , or equivalent to 15, the horizontal reference. |
5.4. | Rotate the propeller shaft slightly to centre the bubble to the indicator. The U-joint is now vertical. |
5.5. | Without disturbing the setting on the J-23498-A Driveshaft Inclinometer , or equivalent, remove the J-23498-A Driveshaft Inclinometer , or equivalent from the rear U-joint bearing cap. |
5.6. | Install the J-23498-A Driveshaft Inclinometer , or equivalent to the lower U-joint bearing cap of the front U-joint of the same shaft. |
5.7. | Observe and record the reading of the front U-joint with the J-23498-A Driveshaft Inclinometer , or equivalent still set to 15, the horizontal reference. |
- For prop systems with 3 U-joints, rotate the shafts 1/4 turn and repeat steps 5.1-5.7 for the other prop shaft.
- If the difference between the front and rear U-joints of a welded yoke propeller shaft is 3 degrees or less, the propeller shaft is properly phased.
- If the difference between the front and rear U-joints of a welded-yoke propeller shaft is greater than 3 degrees, the propeller shaft is either constructed improperly, or damaged from twisting. Refer to Propeller Shaft Phasing Correction .
- If the difference between the welded yoke and slip yoke of a propeller shaft is 1.5 degrees or less, the prop shaft is properly phased.
- If the difference between the welded yoke and slip yoke of a propeller shaft is greater than 1.5 degrees, the propeller shaft is either constructed improperly, or damaged from twisting. Refer to Propeller Shaft Phasing Correction .
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