Well, I need to sign myself up for this forum. Wish I had grabbed a pic of the load. I needed to move (4) large concrete blocks. I figured each block weighed 2,000lbs. I knew my trailer had a 10,000lb capacity so I figured I was good. Well, I noticed the trailer had really compressed the suspension and the truck was sagging despite the leveling bars. Figured it was just the way I had loaded the blocks (2 over the axles, one sideways behind and one lengthwise in front). Well, when I went to move the truck it didn't want to pull the load. Got it moving and noticed that it took full effort to provide effective braking. The trailer felt really heavy, but I only had a couple of miles to go on country back roads.
Well, this morning I looked up the block weight and they are actually 3,600lbs! That means the load weighed 14,400lbs! Add in the unknown weight of the trailer and I was probably over 17,000lbs. Even with the max tow option, that is way beyond the capabilities of my f150.