No, axles should not be bent. To double-check you would need a known straight-edge, like a level or a 'square' (which is actually shaped like an L), and hold that up against the axle(s) If you see light between the two then the axles are not 100% straight. The measuring tool should be pretty long, approximately the same length as the axles.If this measurement technique is not possible, you may be able to measure from the ground to the axle tube at several intervals. This might reveal any discrepancies but they would have to be significant enough to measure. Apparently, yes in some cases., an online merchant of trailer related items:Trailer axles typically have the bow. In them to helpcompensate for the vertical load they bear and still have proper wheelcamber. This way when the load is put on them the axle will flattenout and the wheels will be aligned properly.Square axles are a bit of a wild card though as they aren't asstandard as the round tube axles.

• Straightening A Bent Trailer Axle

I have seen totally straight onesand I have seen curved ones.The purpose and effect of this curvature is further elaborated in:Most trailer axles are designed with a “bend” in the tube that willdeflect when the load (weight of the trailer) is applied. This willtheoretically bring the trailer wheel camber toward a 0 value that isthe best setting for most trailer applications. This will allow thetires to wear evenly and allow the longest tread life.Both Sprung axles and Torsion axles typically are built with a slightpositive camber but custom axles can be specified with or withoutcamber. A trailer that runs long distances without a load may bebetter without axle camber. An example of this might be a longdistance boat transport trailer.As to whether the bend would be visible: at minimum if you held a straightedge up to the axle (long level for instance) it should be visible.

Straightening A Bent Trailer Axle

It may be hard to detect otherwise, particularly because you often can't get a good unobstructed view of the axle.Just because some axles have deliberate curvature doesn't mean all bends are good! The axles the articles are describing would I think always have either a consistent, gentle curve or at least be symmetrical. This is distinguished from bends from damage which would almost certainly not be symmetrical (left-right) and could show other signs of proximate damage from whatever caused it.(In my own experience, on the bent axle on my now wrecked utility trailer the bend occurred at a relative weak point - where the wheel / hub spindle met the thicker part of the axle.).