A universal joint operating angle is the angle that occurs between the driving member and driveshaft, and between the driven member and driveshaft when they are not vertically aligned. NOTE: This calculator does not address compound drive angles (horizontal offsets).
You’ll need a protractor accurate to ¼ degree (Spirit level or digital protractor), and you’ll be measuring angles at various points, from the transmission, along the drivelines and back to the rear axles.
Enter the angle to the nearest ¼ degree, along with the slope (up or down):
Up: Rises from front to rear of vehicle
Down: Descends from front to rear
3 ways to measure:
- Adapters available for digital protractor to allow for measurement of slopes directly off bearing caps in light duty or quick disconnect applications
- Remove bearing cap and take measurement directly off yoke
- Remove snap ring take measurement off bearing cap using adapter
Measurement Tips:
- Measure along actual center line of output shaft
- Measure on flat surface 90 degrees to or parallel to output shaft of transmission
- Measure true center line
Basic Rules:
Rule 1: Universal joint operating angles at each end of a driveshaft should always be at least one-half degree
Rule 2: Universal joint operating angles on each end of a driveshaft should always be equal within one degree of each other (one half degree for motor homes and shafts in front of transfer cases or auxiliary devices)
Rule 3: For vibration-free performance, universal joint operating angles should not be larger than three degrees. If they are, make sure they do not exceed the maximum recommended angles.
| Drivehsaft RPM | Max. Operating Angle | Interaxle | |
|---|---|---|---|
| Parallel | Intersecting | ||
| 5000 | 3.2° | — | — |
| 4500 | 3.7° | — | — |
| 4000 | 4.2° | — | — |
| 3500 | 5.0° | — | — |
| 3000 | 5.8° | — | — |
| 2500 | 7.0° | — | — |
| 2000 | 8.7° | — | — |
| 1500 | 11.5° | — | — |
The angles shown on this chart are the maximum universal joint operating angles recommended by Spicer engineers and are directly related to the speed of the driveshaft. Any universal joint operating angle greater than 3 degrees will lower universal joint life and may cause a vibration. Remember to check maximum safe driveshaft RPM by using the Spicer safe operating speed calculator.
