Daryo Feb 8, 2021:

That would suppose an extremely rigid frame or a link between the frame and the body that has some in-built "play" - which seems a credible explanation for a "torsion-free" link between the two. Yes, that would make sense.

Tony M Feb 8, 2021:

@ Daryo I think you're looking at this "the wrong way round" — I read it that the body is mounted (to the chassis) in such a way that it (= the body) is not subjected to torsion even when the vehicle is moving over uneven ground.

Daryo Feb 8, 2021:

do you have ANY indication as to what exactly is being "mounted" on what exactly?

The body of a car / truck would normally be assembled WITHOUT any in-built "torsion" (no one sane would do that) so by default in any case the "torsion" would not be in the body itself of the truck - IOW it would be pointless to make a selling point of something that is true by default;

what would makes sense is that there is s.t. that is mounted on the body of the truck is a way NOT to generate any effort of torsion at the assembly point.

Any more details?

Is there a separate frame / chassis or is the body "une caisse autoportante"?