I bent the frame on a loaded 18k gvwr GN trailer by jacking the frame from a single point in my younger and dumber days......even after my equipment trailer mfg said not to. Lessons learned the hard way.
I carry a old truckers special 12t shorty hyd jack that is made to slip under a axle tube (leaf spring suspension) next to the U bolt. The old jack has lifted one end of 1750 lb-8000 lb axles from the tubes on fully loaded trailer with Dexter or Rockell American axles. In all those years and over 1.2 million miles on the road never saw or heard of a tube being crushed till I came on a RV website.
No tube damage is the result of the fact lifting one end of a 6k axle a bit is only 2500-3000 lbs vs the whole side of a 12k trailer till the suspension relaxes and the tire clears the ground.
Everyone has their method....this is just mine.
