I blew out the rear U-Joint on my '03. While trying to determine where the "clunk" was coming from under the truck, I drew a line on the shaft coming out of the differential and matched it up with a line on the differential. When I shift from Drive to Reverse and back again (with the e-brake on) I'm getting almost 10* of play in the shaft coming out of the differential. I'm curious to know if this is too much play?

 

10 degrees is fine for how you are mesureing it.