I found the problem, using the gear marking compound I can see 3 or 4 teeth on the pinion with a distinct line running across the tooth,it is shiny so it is a high spot. It does this exactly where it makes the noise! Then I did a test on the ring and it left a distinct line on 2 of the teeth on the ring also. So i'd say these were messed up to begin with like I had assumed all along.......I am going to try and get them exchanged as they only have 500 miles on them and this problem existed from the beginning. I am not sure how it will go as the truck has been stored for one year which the warranty states 6 months.......I bought them from National Drivetrain not sure how there rep is?