There are several different parameters that are very important to finding a new axle for a trailer. The most obvious is the Gross Axle Weight Rating that defines the load properties of the axle (and trailer). Typical values of GAWR are 2200 lb, 3500 lb 5200 lb etc.
Other values that are important in defining a trailer axle are Track Length (center of tire to center of tire), Overall Length and Spring Center (center of spring to center of spring).
Camber is another property that is defined by the trailer axle. Actually, camber is the effect of the tire alignment on the pavement as illustrated above.
Most trailer axles are designed with a “bend” in the tube that will deflect when the load (weight of the trailer) is applied. This will theoretically bring the trailer wheel camber toward a 0 value that is the best setting for most trailer applications. This will allow the tires to wear evenly and allow the longest tread life. Camber can be affected by damage to the axle. For example, if the axle spindle is bent, this will usually cause a negative camber on that side which will cause excess tread wear on the inside of that tire.
Both Sprung axles and Torsion axles typically are built with a slight positive camber but custom axles can be specified with or without camber. A trailer that runs long distances without a load may be better without axle camber. An example of this might be a long distance boat transport trailer.
Axles and related products can be seen online at:
TRAILER PARTS SUPERSTORE ~ AXLES