I'll have to check on the axle size and capacity. Is it listed right on the axle?

This can also be cause by trailering over potholes.

I drove a perfectly good trailer to Massachusetts in October to pick up my Seafari, and came back with exactly the same problem, cause by the extremely rough roads in the North East. Had it checked, and the verdict was that I needed a new axle, as straightening the stubs and spindles costs more than a new axle.

If your problem is just toe, it's an impact forward of the caster point. If you also have camber issues, weight may also be a problem. (As your axle is a torsion axle, you also have to account a little bit for caster position, which affects trail angle)

The axle says axle is 4200 lbs. max weight on the trailer should be 2800 lbs. here are a couple pics of the axle. The frame looks like it's 2 inches by 2 inches.

http://i1326.photobucket.com/albums/...psa3a469a5.jpg

http://i1326.photobucket.com/albums/...ps840d3d34.jpg

Looks like you need a new axle. Question is does it need to be rated higher, probably if you load the boat heavy. You could maybe wait until you get close to the ramp to gas up (50 gals is more like 300lbs btw) and put the ice in the truck on the way there. The trailer appears to be several years old, I was wondering if you bought it new or used. If it was used, you don't know what the previous owner did to it.

As far as trailers go it's really not that old. 2007 model

Seven years could be several. The point is that if the boat has been on that trailer since it was new and it didn't wear out the tires before now, what has changed. Could it have been damaged or is it just worn out. My trailer is 21 years old and I've replaced the axles 'several' times.
I went on the Venture trailers site and clicked on parts and it only had torsion axles up to 3500 lb rating listed. I guess you would have to get the 4200 or 5000 somewhere else. Just trying to help.

Thanks bump, I appreciate the help. I did a lot of trailering this year. I suspect the tires are original, so I will start out with better tires first and go from there before I do a new axle.

I don't know what you might consider "better" tires, but whatever you do, don't put Goodyear Marathon tires on that axle. They apparently perform just fine on most trailers, but I can tell you from first hand experience they tend to explode at the most inopportune times when subjected to continuous lateral loading from an axle with too much in or out toe.

I went through four of them on an axle like yours before I figured it out. I kept returning them for a pro rated replacement. Only one of the four failed while the trailer wasn't moving down the road. Loud booms, tread flying everywhere, very exciting. Even had one that shed its entire tread but held air. It made it down the road (I-75) a mile or so on the steel belts to the next rest station. The fenders on that trailer look like Rodney King after the LAPD got through with him. I don't buy them anymore.

Dave