Did it come with the Dexter spring upgrade? Those zerks look like they have never been used but you should have the bronze bushings with this kit which is a plus. Check the alignment like mike-s suggests but I truly think it's a bent axle. If it were me, I would take the axle out and turn it around and see what happens when it's on the other side...if you get the same wear on that other side and the tire on the side that had the wear is now fine...it is bent. Does that make any sense? But if you get the same wear as before now that would be most likely be an out of aligned axle....take some measurements before you even start to make sure the spring brackets all match on both sides...good luck...its' a head-scratcher.