Loading the cargo box with six bales of hay, which fit perfectly, causes the wheels to clip through the cargo box with any sort of movement. The suspension should be much stiffer, this vehicle was made to carry things, not for a smooth ride. I realize this isn't an ultra high priority issue, but it would make a difference to me.
Fixed, I think. Raised spring rate by 67% and stiffened the bump stops. It can carry a 2.5 ton Vanster without clipping, though I haven't tried 6 hay bales.
The .jbeam for the semi's F and R suspension were updated on August 4th in the files I have from the new update, the R wheels were updated on August 7th, and the main truck .jbeam was edited July 31st. Unless those are the wrong files for the changes you made, I'd guess from the dates that they might be the newer versions but it depends on when you made the changes before or after your first reply.
I made some changes to wheel and suspension files late last night (technically August 7th) so it could be that those changes made it in, but not today's fix for the HD rear suspension.
If you want you could list the values of the responsible line in your version, and I'll list what the same line is in the latest update.
Oops. Van heavy duty suspension and wheels were all updated August 7th, the cargo box itself - which probably doesn't affect suspension but will list for clarity's sake - was edited July 31st.