Here's some information I posted years ago but think it bears repeating. This is a 11:26 long video that takes all the mystery out of driveline angles, how to measure them electronically, and how much angle is "too much".

Below I also provide a link to the free app used in the video. Enjoy!

https://youtube.com/watch?v=f1m-Fh5kiRU

https://play.google.com/store/apps/details?id=com.plaincode.clinometer&hl=en

Larry from Utah