The left hub on the Carpet Knife is a dual 2 bolt/3 bolt design. If you use the 2 bolt setting with 3 bolt rear wheels, your rear width will be way off.

The shorter flange goes toward the bearing for the 3 bolt configuration. You will also notice that the 3 bolt rim slip fits over the opposite "longer" flange when correctly installed.

I would bet right now you have the longer side pointed in instead of having the wheel mounted over the longer flange/wheel boss.