On the page with all the pictures they have 2 pics from the bottom where you can see the rear axles. I'm pretty sure it has a rocker. I agree it's a toy but it's cute. I'd think it'd be a neat 1/2 ton truck for like you say an RV or 7000lb trailer with small tractor. I think it'd look just a cute with the 5th wheel removed and a box van body on the back and it would make a lot of space for a business to advertise while they were delivering stuff.
One thing it'd need for me--an air conditioning unit on the top the cab like some old semis had--for functionality.