I ain't watched the whole video yet but hub nut shouldn't come loose with an air impact, but they need to be pretty tight. I have stock axle nuts and the 2 wrenches required to tighten them, but they kept coming loose... I finally used red locktite and that did the trick. I bought ny first 400EX in 2000 best quad ever. I run the blue jug Rotella T6 synthetic in everything I own for a long time. Equate/walmart hand sanitizer for grips