Our trailer is dog tracking to the driver's side and would appear to have an alignment issue. We were able to correct this and make it a lot better than it was. Still have some other issues we will have to work through to get it 100% by just moving the front axle we were able to make it track much better and ride smoother.

Help full hints:
Both side U-bots need to be loose in order to move the axle.
also, use a straight 2x4 with the wheels on and make sure both all edges of the tire touch the 2x4 to make sure both axles are straight with each other
don't forget to tighten up all the bolts after your done