Joint Working Angle Limits (Parallel)
Universal joints have a maximum working angle, depending on type and manufacture. It is recommended that the joint working angle for parallel joint assembly not exceed 8 degrees for main drivelines over 40″ long. For main drivelines under 40″ the maximum angle should not exceed Length (L) divided by 5. (This limit does not apply to interaxle drivelines.)
Example: For a 35″ driveline, the maximum joint working angle would be 35 plus 5 or 7degrees. This working angle must not be exceeded.
Place protractor on driveline to obtain angle of driveline from transmission to axle. The difference between the driveline angle and the joint angle is the joint working angle. For instance, if the transmission is 3 degrees down, and the driveline angle is down 7 degrees, the transmission joint working angle is 7 minus 3 or 4 degrees.
On tandem drive or auxiliary installations, take readings in the same manner, comparing the universal joint angles to the driveline angle to which it is attached.