Every trailer's lug nuts need a break in period. The lug nuts are to be retorqued to spec (we will tell you) at the initial 10 miles of travel, then at another 15 miles, then lastly, at another 25 miles. 
 
This is to be done any time the wheel was removed from the hub or the lugnuts loosened.
 
This is not a torque wrench but it will help in a pinch.