Originally Posted by Inland RV Center, In
Misalignment of axles, caused by an improper location, will cause the trailer to tow dog-legged, and excessive tire wear.
The easiest way to tell, is measure from the lowest forward edge of the axle mounting plate, to the center of the jack post, on each side of the trailer.
That dimension should be "exactly" the same.
I would suggest that a steel tape measure be used, along with 2 people to make an accurate measurement.
There are 2 fixes.
The first, and most expensive, would be to reshape the axle tubes.
The second, is to open up the 5/8 inch holes on one side, so the axle can be relocated dimensionally. It will also be necessary, in most cases, to enlarge the square cut out in the axle mounting plate, where the axle tube is located.
As a final measure, install one additional bolt at least 1/2 inch, thru the axle mounting bracket and thru the axle mounting plate, after the axle is relocated.
That will keep the axle in it's correct location, should the 5/8 inch bolts come loose.
When relocating holes like this sometimes you can add a washer under the bolt head and weld the washer to the frame.
I have seen this done when repairing a bent car frame and it is necessary to move the wheel slightly to get perfect alignment. You have to slot the mounting holes then add the washers so the part cannot move.
Get everything lined up perfectly, then tack weld the washers in place.