Don't take my word for it but it has been my understanding in camping with a lot of Boler
Peeps that the trailing arm on the Boler
started out new with the arm level with the frame.
Steve, do you have any photos of the trailer with the wheels on it sitting on the ground to share?
Other indicators that you need a new axle
are uneven tire wear, lack of clearance (a hand wide or less) at the top of the tire to the wheel well, black marks on the wheel well indicating the tire has been hitting it on bumps.