Suspension Help Needed

[62gaser]

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 You
Danny

[alboy]

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]

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]

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]

Probably normal chucking due to road conditions. Some roads will cause it some will not.

[valhalla360]

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]

What model (number) is your Flagstaff and what is its GVWR? What is the payload on your truck?

Rob

[bsbeedub]

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]

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]

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

[time2roll]

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.

[agesilaus]

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