Nineback,
Prudence is one thing, legal is another. Just about any rig with.a single due Axelrod is legal to 20,000 on that Axel. Not saying smart in the case of most 35 series trucks......
A sing tire pickup with typically 9-12" tires, will be over weight in the 9,000-12,000 lb range. Again, the weight cops enforce max load the road can handle, is designed for etc. They do not enforce manufacture warranty performance specs.
I've been pled over in most with 17000-19000 on manufacture capacity of 12000 on rear axel, no over weight ticket, as y tire widths totaled more than 20000, I was under 20000, and paid for licence was higher than I weighed. I was paying my.share of road tax for the.damage I was doing to the road. That is what is enforced!
Marty