Driveline Working Angles Measurement

Driveline Working Angles Measurement


Tools Required
* J 23498-A Driveshaft Inclinometer
* J 23498-20 Driveshaft Inclinometer Adapter






The working angle of a U-joint is formed by the difference between the angles of two shafts that intersect. One-piece propeller shaft systems have two working angles; front (1) and rear (2).

* The front working angle (1) is formed by the intersection of the transmission output shaft and the propeller shaft.
* The rear working angle (2) is formed by the intersection of the propeller shaft and the drive axle pinion.


When measuring and evaluating driveline working angles, observe the following:

* The two working, or cancelling angles should be equal to each other within 1/2 degree to provide effective cancellation of the U-joints.
* No working angle should exceed 4 degrees.
* No working angle should be equal to zero. An angle of 0 degrees will cause premature U-joint wear due to a lack of rotation of the needle bearings in the U-joint.
* Always orientate theJ 23498-A so that it faces the same side of the vehicle for each measurement taken.




* Be sure to accurately record the measurements taken on a diagram, similar to the one shown.



Measurement Procedure

Important: If it is necessary to use theJ 23498-20 adapter, first verify the accuracy of theJ 23498-20 by inspecting the angle of an accessible joint using theJ 23498-A , then inspecting the same joint angle using theJ 23498-20 .



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 toLifting 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 L (1 gal) of gasoline is approximately 2.8 kg (6.2 lb).
4. Clean any corrosion or foreign material from the U-joint bearing caps.
5. Remove any of the U-joint bearing cap snap rings that may interfere with the correct placement of theJ 23498-A .




6. Measure the angle of the drive axle pinion.

1. Rotate the drive axle pinion to align the pinion yoke flanges vertically.
2. Install theJ 23498-A to the lower U-joint bearing cap of the drive axle pinion.
3. Using theJ 23498-A , measure and record the angle of the drive axle pinion.





7. Measure the angle of the transmission output shaft yoke.

1. Do not rotate the propeller shaft. With the propeller shaft in the same position, the transmission output shaft yoke flange will be aligned vertically.
2. Install theJ 23498-A to the lower U-joint bearing cap of the transmission output shaft yoke.
3. Using theJ 23498-A , measure and record the angle of the transmission output shaft yoke.

8. Rotate the propeller shaft 1/4 turn.
9. Measure the angle of the propeller shaft.

1. Do not rotate the propeller shaft. With the propeller shaft in this position, the U-joints of the propeller shaft will be aligned vertically.
2. Install theJ 23498-A to the lower U-joint bearing cap of either of the U-joints on the propeller shaft.
3. Using theJ 23498-A , measure and record the angle of the propeller shaft.

10. Remove theJ 23498-A .
11. Install any U-joint bearing cap snap rings that were removed prior to installing theJ 23498-A .
12. Calculate the working angles at each intersection of two shafts.
Subtract the larger number from the smaller to obtain the working angle. For example: If the drive axle pinion has an angle of 16 degrees and the connecting propeller shaft has an angle of 13 degrees, then the working angle of that intersection is 3 degrees.
13. Compare the working angles of cancelling U-joints, beginning at the rear-most position.
14. If the working angles of two cancelling U-joints are not within 1/2 degree of each other, or if one or both of the angles exceed 4 degrees, then the angle requires adjustment.