same here, i originally only did dual shackle cause I was lazy, but it has been working fine for me. I dont even have bumstops that stop it on the frame, and it doesnt make any noise? Also, I have dragged the nose of the truck down stuff, with no unloading at all.
The only time i hear mine, is when i'm hitting bumps, big bumps, really fast one after another. then i start hearing the shackel on the frame moving around. besides that, i don't here it.
