2. One unique aspect of the 2 1/2-ton Rockwell axle is the hub. Interchangeable from front to rear, the massive six-lug hub can be flipped in or out to modify your axle width. One important thing to note about the wheel studs is that one side of each axle will have lefthand studs. While many don't seem to mind the mix-up, a few chose to swap out the lefts for a standard righthand thread to avoid confusion when your buddies can't figure out why your impact can't break your lug nuts loose.