Broken wheel stud and lug nut.

Originally Posted by ChrisSlicks

Well it seems like they are torqued correctly but what actually is happening is that the stud bottoms out in the nut before the taper makes full contact with the wheel. So it will seem tight at the time but within just a few miles they will start backing off. Mine were only on there for about 40 miles and had backed down from 80 ft/lbs to probably 50 ft/lbs, I can only imagine with a few more miles they would have gone finger tight and eventually probably fell off on their own.