[Keith Seymore]

Originally Posted by Keith Seymore

There are two u joints in the shaft, each generating accelerations and decelerations as they rotate (two kicks per rev of the shaft).

The u joint working angles at each end need to be equal and opposite in order for those forces to cancel out.

K

Additionally, the u joints don't care about the orientation of the individual components or the frame or the ground: only the difference between the two.

The vehicle could be on its side and the u joint working angles would be the same*.

K

*barring any changes in suspension compression, of course.

K