measure between the tires, (inside to inside) front,back,top and bottom. If there are any large differences this will show it. they measurements should be very close to the same. What type of
axle do you have is it a torsion? if so jack up the trailer and check fo play, in the wheel bearing and in the axle.
My box trailer was out by an inch front to rear, and it ate a set of tires in about a thousand miles.