F-350 and cocrete

Free way hop...can be common with certain truck trailer combinations on certain well used concrete highways.
There is a whole list of things folks do to help their combinations. And what works on some does't effect others.

Many folks with severe free way hop (chunking) go with some type of air suspension pin box.

Some have moved the aux upper over load spring pack so its not as aggressive.

Others may change to a larger diameter tire on the truck.

I fixed a chunking issue on on one of my 3500 DRW trucks by moving the trailers spring hangers aft by 2". The other four 350/3500 DRW trucks pulling the same trailer with no chunking issues before or after the axle move.

Good luck on your search as it can be a very aggravating problem to get a handle on.

What kind of hitch do you have? You get what you pay for. I have a 36ft 5th wheel and I have a 25k air safe hitch with the Binkley Holland head. My wife even said ,that you don't know the 5th wheel is behind us. With that hitch,when we are going down the highway.
If you are hook up solid. Then the 5th wheel and the truck is going to feel everything the other one does. Instead of the 5th wheel being independent of the truck and floating on air.

Know your rear axle load. Use the tire/weight inflation chart for your tires add 5psi to what the chart lists. Install Bilstein 4600 shocks. If you are not satisfied add air bags and run about 25-30psi when hitched.

Have a B&W Companion hitch and Firestone air bags. Same issue with or without trailer...

Although hard to get rid of, I try to increase speed, or lower speed, and move left/right from the normal worn driving lines in lane. One or all of these driving adjustments, should net a 50 percent improvement.

Jerry

My crew cab long bed does the same thing. It's the distance of the expansion joints in the concrete that set up a oscillations in the truck. The wheelbase is just right for this to occur. I put on air ride suspension and pin box that helps. Agree with slowing down helps as well.

Some roads are just awful, face it. In the family sedan, you'll never notice. But get in a truck and especially pull a trailer, it can be awful. A lot has to do with how aired-up your tires are. But still, the suspension on a truck is stiffer than the family sedan, for sure. So every crack in the road is felt. For this reason, I quit driving interstates, because they are so rough on the truck and feel like I'm beating it to death. Where bridges join, where construction has occurred, on concrete roads, there nothing forgiving with a truck. I've run into sections of interstate where I've had to slam on my brakes because the truck started bouncing so hard I though I'd loose control. The only thing I have found to help, is less pressure in the tires.

Cummins12V98 wrote:
Know your rear axle load. Use the tire/weight inflation chart for your tires add 5psi to what the chart lists. Install Bilstein 4600 shocks. If you are not satisfied add air bags and run about 25-30psi when hitched.

Okie1 wrote:
Have a B&W Companion hitch and Firestone air bags. Same issue with or without trailer...

X2 To Cummins12V98 states, this also applies to the empty issue. With DRW should drop rear tires to between 35 to 40 psi, you don't want to be like the Flintstones and ride on rock hard tires.
Deflate air bags to minimum pressure empty.
Does your 5er have shocks, if not install some!

Just let it go, as the little girls sing. Of course I came from trucks, and find it normal.

All concrete highways? Or just some of them? Some are much worse condition than others.

I have a 2012 F350 SRW long bed pulling a 35' 5er. Occasionally I hit a concrete highway that rides a little rough. But for the most part the ride is good on the interstates.