Welcome to the forum.
Can you clarify? It sounds like you want to flip the axle
If so, look under the trailer from the back, or better yet, put a good straight edge on it. I think you will find that there is an upward bow in the axle
, from end to end.
Most axles have this arch. It's not much, but it is there to provide the positive camber to the axle. Positive camber gives the wheels a slight inward tilt at the bottome. The purpose of positive camber is to allow for deflection when the trailer is loaded.
If you flip the axle, you will end up with negative camber, which will go more negative when loaded and the trailer is likely not to track right.
Go here for and explanation:
TRAILER AXLE CAMBER ~ WHAT IT’S ALL ABOUT