Driveline Working Angles Measurement

Driveline Working Angles Measurement

Tools Required

J 23498-A Driveshaft Inclinometer

The working angle of a U-joint is formed by the difference between the angles of two shafts that intersect. The propeller shaft system on this vehicle incorporates 2 U-joints, and therefore has two U-joint working angles.

* The forward working angle is formed by the intersection of the front and rear propeller shafts.
* The rear working angle is formed by the intersection of the rear propeller shaft and the drive axle pinion.


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

* The U-joint working, or cancelling angles should be equal to each other within the range specified in this procedure 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 the J 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

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. Inspect the lateral alignment of the propeller shafts before proceeding.

1. From underneath the propeller shafts, look down the length of the shafts from front to rear. Inspect the alignment of the shafts to each other.
2. From underneath the shafts, if the propeller shafts are not aligned to each other in a straight line, then the lateral alignment of the propeller shafts needs to be adjusted before proceeding.
The propeller shaft support bearing assembly can be relocated slightly to one side in order to improve the alignment of the shafts. Ensure that you do not create a ground-out condition against the exhaust or any other component.

3. Place the transmission in NEUTRAL.
4. 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).
5. Clean any corrosion or foreign material from the U-joint bearing caps.
6. Remove any of the U-joint bearing cap snap rings that may interfere with the correct placement of the J 23498-A .




7. Measure the angle of the drive axle pinion.

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

8. Measure the angle of the front propeller shaft.

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

9. Rotate the propeller shafts 1/4 turn.
10. Measure the angle of the rear propeller shaft.

1. With the propeller shaft in this position, the U-joints of the rear propeller shaft will be aligned vertically.
2. Install the J 23498-A to the lower U-joint bearing cap of either of the U-joints on the rear propeller shaft.
3. Using the J 23498-A , measure and record the angle of the rear propeller shaft.

11. Remove the J 23498-A .
12. Install any U-joint bearing cap snap rings that were removed prior to installing the J 23498-A .
13. Calculate the U-joint working angle 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.
14. Compare the difference between the 2 working angles of cancelling U-joints to the following specification:

Allowable range of difference between cancelling U-joint working angles: 0.25 degrees to 1.0 degrees

15. If the difference between the cancelling U-joint working angles is not within the specified range, then the angles require adjustment.