My wife and I purchased new Forrest River, Flagstaff, Classic Friday. We are first time buyers and very pleased with the new member to our family. I have a 2018 F250, 4X4, 6.2 Gas motor, 6 speed transmission. The truck is stock all the way. When we was pulling the 5th wheel home (first time to pull anything like that) the truck was bobbing up and down a lot and some times it was a pretty wild ride. it looked and felt like the truck held the 5th wheel good but the ride was terrible. I'm mechanically inclined and feel like the shocks were way too soft. Please give me some ideas on how to solve these issues. She is going to sit in the yard until I get this figured out and that's not what we purchased it for. All inputs are welcome.Thank YouDanny

Is the hitch correctly located over the rear axle? What model hitch?

Can depend on the road surface. Some roads can develop a harmonic that matches your truck/trailer to amplify the bouncing. Yes shocks may help. I would try a different road or a newly paved area so see if it changes.

DEMCO 5th Wheel Hitch RECON and yes it is mounted in the correct location.

Load the trailer up. The pin weight might be too light when the trailer is empty, especially if it is a rear kitchen model. Properly balanced you should have 20-25% of the trailer weight carried on the pin. Too tail heavy can cause porpoising.Make sure the truck rear tires are aired to max pressure as well. If those things don’t help try new shocks.

time2roll wrote:Can depend on the road surface. Some roads can develop a harmonic that matches your truck/trailer to amplify the bouncing. Yes shocks may help. I would try a different road or a newly paved area so see if it changes.We just recently bought our first 5er too and I had the problem mentioned above. Certain roads have done this to me. The ride was so bad it concerned me at first but then I realized that the distance from the truck back tires to the trailer tires was just in the wrong place with the slight bumps on the surface of the road. When I get on a smooth road there is absolutely no rough ride whatsoever. I hope you find this is the same as what you’re experiencing.

Suspension Help Needed | Good Sam Community

alboy
Explorer
Jun 15, 2021
Try carrying 30/40 gal of water in the fresh water tank ,it should help settle the bounce.Even with it loaded I WILL Help ABSORB rough road conditions.
garyp4951
Explorer III
Jun 15, 2021
If you are not over weight get some Bilstein shocks for the truck, and if it still bounces add air bags to help the suspension.
QCMan
Nomad III
Jun 14, 2021
Galloping Gertie syndrome. Mostly occurs on concrete highways built over slightly unstable ground. It happens with tt's also. Meant to pack down lunch so you have room for those home made cookies you brought with you.
allen8106
Explorer
Jun 14, 2021
Probably normal chucking due to road conditions. Some roads will cause it some will not.
valhalla360
Navigator
Jun 14, 2021
Second Chance wrote:
What model (number) is your Flagstaff and what is its GVWR? What is the payload on your truck?

Rob

Try taking it to a local CAT scale and get some real numbers.

Ideally, have it fully loaded as if you were taking a trip.

Weight it twice:
- Once with trailer connected.
- Once with just the truck. (costs something like $2.50 for a reweigh)

My guess is something is off with the weights but hard to say without real numbers.
Second_Chance
Explorer II
Jun 14, 2021
What model (number) is your Flagstaff and what is its GVWR? What is the payload on your truck?

Rob
bsbeedub
Explorer
Jun 14, 2021
time2roll wrote:
Can depend on the road surface. Some roads can develop a harmonic that matches your truck/trailer to amplify the bouncing. Yes shocks may help. I would try a different road or a newly paved area so see if it changes.

We just recently bought our first 5er too and I had the problem mentioned above. Certain roads have done this to me. The ride was so bad it concerned me at first but then I realized that the distance from the truck back tires to the trailer tires was just in the wrong place with the slight bumps on the surface of the road. When I get on a smooth road there is absolutely no rough ride whatsoever. I hope you find this is the same as what you’re experiencing.
camp-n-family
Explorer
Jun 14, 2021
Load the trailer up. The pin weight might be too light when the trailer is empty, especially if it is a rear kitchen model. Properly balanced you should have 20-25% of the trailer weight carried on the pin. Too tail heavy can cause porpoising.

Make sure the truck rear tires are aired to max pressure as well. If those things don’t help try new shocks.
62gaser
Explorer
Jun 13, 2021
DEMCO 5th Wheel Hitch RECON and yes it is mounted in the correct location.
time2roll
Nomad
Jun 13, 2021
Can depend on the road surface. Some roads can develop a harmonic that matches your truck/trailer to amplify the bouncing. Yes shocks may help. I would try a different road or a newly paved area so see if it changes.