Frame Stiffing to reduce Porpoising?

valhalla360 wrote:
Plus what happened to the idea you were at 5000lb and suddenly you have 2000lb left over?

In my original post, I was going off what I recalled on my head. In the last post, I was going off the facts based on what I was able to look up. I have weighed the camper before and my recollection is it was close to 4000lbs but I don't recall if that was loaded or empty. I'm sure it was at least partially loaded, at least with bedding and kitchen supplies. I probably should weigh it again and write it down somewhere.

I did not realize the frame was pretty much the same all the way up to 2016. The payload capacity for the 2016 according to Ford was 6460 pounds for a Dually, Long Bed Crew Cab 4x4 and 6870 pounds for a 4x2 configuration.

https://cdn.dealereprocess.org/cdn/brochures/ford/2016-superduty.pdf

That contrasts with the 1999 with Max Payload for the Crew Cab Dually Long Bed 2x4 appears to be 5355lbs and the 4x4 is 4910lbs.

https://www.xr793.com/wp-content/uploads/2016/10/1999-Ford-Super-Duty.pdf

So, with basically the same frame, how did they manage to get another 1500+ pounds of payload capacity out of it? I'm sure there were some upgrades like additional cross members and such but does that account for all of the increased payload capacity.

Every truck frame flexes to some degree. If you don't think your frame is flexing, you probably just aren't looking for it hard enough. The porpoising I am describing is noticeable only on rough roads or rough transitions in the pavement. It isn't happening all of the time nor is it a problem to drive it as is. I did see the story about the grossly overloaded truck that broke the frame in half in Mexico and yes, it did get me to wondering if one could strengthen the frame but no, I'm not concerned the same will happen to me. I'm confident I am within the capability of my truck.

It does appear that I am in uncharted territory with thinking about stiffening the frame.