Yea, well, apparently you are allot better at judging than I am.
My trailer is very easy to overload. Single axles really kind of suck for wood hauling as my 5x10 is a pretty small floor and if you calculate it out as little as a 16-18" high load could be overloaded. Also keep in mind this is not the light duty version you would find with the lighter axle and 12 or 13" rims and tires like at most of the big box stores or farm stores. It has the full 3,500# 5 lug axle with 15" rims and D load range tires. Well, I did just that and misjudged last year. I bucked up a big trunk into 16-18" long rounds. Carted them on the trailer standing up in just one layer tall and "thought" that should be an ok load. As soon as I pulled out on the road and stepped on the gas I knew it was very heavy. Luckily it was back roads all the way home so I just took it easy. Once split and stacked it was about 3/4 of a cord and by how heavy the wood was (green fresh cut sugar maple in the spring) it was probably about 3500#. The rear gate on the trailer has never quite closed right since then.

I was also on a scrounge last year grabbing some black walnut. It was close to home, getting dark, and I had to work the next day so I was cutting and throwing it in the back of the truck as quick as I could. I filled it up to the bed rails and headed for home. Took off down the road and suddenly realized my F150 felt like a 1950 Buick with four flat tires

. I really didn't even want to drive 2 miles home it was so bad. Split and stacked that out to a little over 1/2 cord or about 2500# in my poor F150. No, it actually was not squatting in back at all, but upon closer examination when I got home the whole truck was sitting 4-6" lower than empty and looked like a 2wd instead of a 4x4. I just thought it was easier to get in the truck when I left because I was on a hill.