The thunk is probably the bar turning and hitting the mount, my car does it too.
ok. i am going to weld it just for safety either way. it kinda bugs me how i read of a handful of people snapping the mounting bolts before it even hit 47 ft/lb. i went by hand on mine, but they are tight. the bracket as i said, is bowing in. i could not fit a spacer in. i must have one of the thicker frame rails. their spacers for sure would not fit, the drivers side seems good with the rail width.
with it welded, it wont bug me atleast. i am going to try and figure out the thump for sure. i have a spot where i turn around where it does the thump everytime at the same spot. i'm tryin to narrow stuff down based on the cars movement.

