Shawn, what size (width) are the utility trailer tires and what does the trailer weigh? I wouldn't be surprised if the Scamp tires are relatively heavily loaded for their size.
Also, the Scamp likely has a higher centre of mass (center of gravity) than the utility trailer (with load), so it will be harder on the outside edges of the tires when turning.
Even considering the undersized tires, 10,000 km doesn't seem like very much tire life to me.
Typical tire width of your pick up truck, I think I am running 235/75/15 this time around but I would have to look. I find that after five years, at most I get a scalloped effect on my utility trailer, but its home made, first regristered in 71-72 timeframe with a 50 era Ford front end and rims. I expect weird things from my utility trailer, parts of it are older then I am, and I am getting to the age where weird things start to happen
On the scamp, I cannot determine any axle
damage, but it is an 85 so it is most likely tired. I have noticed damage to one rim and a hub from the lugs becoming loose at one time. I think I just put 2 and 2 together with the shell damage
A wheel fell off this Scamp! It was drug on its right side most likely causing damage to the axle
as well! Nuts! The frame looked ok when I had the floors out but I did not lift the shell off, I should have but I did not take the kitchenette floor out as it was not rotten. When I redid the floors, I discovered the lower right corner had been completely replaced from about the corner marker to front center and the front bench had been repaired as well. The top has an exhaust burn that is now visable since the paint
repair peeled. Adding it all together, I think I know what happened to this poor little Scamp one day in its life, things you wish you were told when at the time of purchase. I don't know if this helps in the repair now, but thanks for listening as a few things are making more sense after typing them out. I may need a new axle
edit for spelling and add tire photo