Crappy Lippert torsion axles
I have a 2012 Visa. They changed the name to Vista Cruiser in 2013. Mine had a 3,500 lb Lippert (China) torsion axle. My GVRW is 3,850 lbs. Can you see the problem right away? The first axle failed in 700 miles. They replaced it ASAP. The second one failed in 500 miles. I called and asked how they could get away with the undersized axle. It was explained to me that 350 lbs are on the tongue. RIGHT!??? I decided that to keep throwing a 3,500 lb axle on a 3,850 lb trailer was stupid. I had my shop replace the crappy Lippert with a 6,000 lb Dexter (USA Made) torsion axle. Dropped right in with a little trimming of the wheel wells. It put the tires about an inch behind the original location. If I had to do it all over again I would replace the whole torsion axle with leaf springs. It can be done, but, you have to weld on some hardware. The frame is also too weak to support the single mounting point of a torsion axle. A leaf spring system mounts on 2 points on each side, cutting the forces on the frame in 1/2.
I agree with Muleman that most trailer repair shops can do the swap. Just be sure to upgrade the axle. Dexter builds all of their axles custom to your specs.