TV/Fifth Wheel combo provide an acceptable ride?

[Garyl53]

We completed a recent trip of about 750 mi. round trip over various roads from highways (mostly) to city streets. Our ride was terrible consisting of constant chucking and general rough riding. I have fought a chucking issue that has improved slightly with additions to TV and 5vr over the past 3 years but DW can't take ride anymore since there is just too uncomfortable preventing her from reading or even using a tablet or phone. It has caused us to reevaluate our plans to travel extensively with this rig after retirement in the next year. My signature shows our rig info. Maybe I have a suspension defect in the trailer or the truck but I haven't been able to resolve it.
What is your ride like?
Is it comfortable for the passenger?
Is that why many move to a Class A, B or C?
Thanks for any feedback!

[NWKomfort350]

4x4ord wrote:
You said you run just enough
air pressure to be off your overloads. I didn't think the F250 had overloads? I think you should try dumping the air out of your air bags. I'm guessing your overload springs are banging oon thier supports. My truck rides very similar towing as it does empty.

Some F250's have overloads. Essentially he has an F350 if it has overloads.

I don't use airbags and my truck rides on the overloads.

I consider my combo to ride quite comfortably.

I agree try running with no air in the airbags so the truck will use its suspension the way it was originally setup.

[4x4ord]

You said you run just enough
air pressure to be off your overloads. I didn't think the F250 had overloads? I think you should try dumping the air out of your air bags. I'm guessing your overload springs are banging oon thier supports. My truck rides very similar towing as it does empty.

[Durb]

JIMNLIN wrote:
Probably because many of us has had chucking issues and what we found was just the opposite of some of durbs opinions that say it won't work.
For example is I found air bags eliminated my chucking issues with a certain combo but I've been around towing trailers since '58 and I have enough experience to know air bags may not work in all chucking problems.
Durb does have some good pointers and reasons a certain combo can have chucking issues but to say this or that will or won't stop chucking isn't true for all combos.

Good point about air bags. Chucking and bouncing are timed events, the kingpin is pushing forward and down at the same time. If air bags made the connection between the hitch and the ground so stiff that it stopped the trailer from rotating then it would stop chucking.

[danrclem]

Garyl53 wrote:
Danrclem - changing the springs was about a two hour job, mostly setting up the jack and jack stands correctly. I just removed the wheels, removed the screw holding the brake line bracket to create some slack, removed the front sway bar from the top of the links and then lowered the axle. Springs can then be lifted out quite easily and replaced. The front height only lowered about 3/4 of an inch.

Thanks for the info. Hope you get everything sorted out.

[Garyl53]

Danrclem - changing the springs was about a two hour job, mostly setting up the jack and jack stands correctly. I just removed the wheels, removed the screw holding the brake line bracket to create some slack, removed the front sway bar from the top of the links and then lowered the axle. Springs can then be lifted out quite easily and replaced. The front height only lowered about 3/4 of an inch.

[Garyl53]

Thanks Durb, very interesting. One thing that bothers me about the chucking I am experiencing is the frequency of the push-pulling force appears much higher than the rotating mass of a trailer could achieve. It also occurs frequently on very smooth newly paved road surfaces. Severe road imperfections or road expansion joints appear to be handled well and well controlled with my Andersen hitch and shocks on the trailer. Also I am surprised that my Mor/Ryde rubber pin box isn't eliminating or reducing the forces more. Perhaps it is really an up/down force that is occurring but the "feeling" on occupants is a push-pull. I am leaning toward the cause being more a situation of the truck spring rates fighting the trailer spring rates. I am working on having someone else tow my trailer to see if there is a difference.

[danrclem]

Gary, did you have any problem changing your springs. I haven't touched mine yet.

Hope you don't have to replace your truck but you might have to in order to get a good tow.

[JIMNLIN]

Probably because many of us has had chucking issues and what we found was just the opposite of some of durbs opinions that say it won't work.
For example is I found air bags eliminated my chucking issues with a certain combo but I've been around towing trailers since '58 and I have enough experience to know air bags may not work in all chucking problems.
Durb does have some good pointers and reasons a certain combo can have chucking issues but to say this or that will or won't stop chucking isn't true for all combos.

[Wild_Card]

Excellent. I have tried to explain this exactly to 50 people that just won't comprehend.

[BarneyS]

This post was written by member Durb. I am posting it for him as he had a computer problem.
Barney

From Durb:
Following is my attempt to explain why a fifth wheel trailer creates chucking forces. Please pardon the cheesy images.

As the front tires of a tandem axle trailer rolls over a bump the front of the trailer lifts up. As the front tires roll off the bump the rears roll up causing the front of the trailer to lower and the rear to lift.


This causes the trailer to rotate around an axis that is parallel to the axles and is located about here.


For demonstration purposes, if the hitch were the same height as this rotational axis all the forces would be bouncing forces (up and down). If the hitch was located directly above the axis all the trailer’s forces would be chucking forces (fore and aft).


Since the kingpin of a 5th wheel is neither horizontal nor vertical to the axis, the forces exerted by the trailer are a mix of bouncing and chucking forces. The greater the angle the more chucking forces relative to the bouncing forces.


There are two ways to alleviate chucking forces created by the trailer. First is to reduce the trailer’s proclivity to rotate. Second is to reduce the hitch angle and reduce chucking forces relative to bouncing forces.

Why does trailer length matter? - Shorter trailers have a built in higher hitch angle so more chucking. In addition to lower hitch angles longer trailers have more polar mass further from the rotation axis so they rotate less.

Why does increasing pin weight help? - Moving mass forward causes the truck to squat more reducing hitch angle. Moving mass forward shifts weight from the axles raising the rotational axis and reducing the hitch angle. Moving mass forward also creates polar mass and reduces the trailer’s tendency to rotate.

Does trailer design matter? - Yes, other than length, trailers with centralized mass such as center kitchens and tanks over the axles rotate more easily. Trailers with weight on the ends (polar mass) are less prone to rotating.

Does axle design affect chucking? - Yes, good equalization and trailer shocks will reduce the tendency of the trailer to rotate. Wider spaced axles will raise the rotation axis reducing hitch angle and also reduce the tendency to rotate. Trailers with stiff suspensions relative to trailer weight will rotate more.

Why does towing nose high increase chucking? - No worse way to increase the hitch angle and increase chucking relative to bouncing.

Does filling the fresh water tank help? – Yes, if the tank is forward of the front axle. This increases polar mass making it more difficult for the trailer to rotate. The extra weight squats the truck reducing the hitch angle.

Do air bags on the truck help? - No, not for chucking. Raising the back end of the truck and kingpin increases the hitch angle and causes the chucking to become worse relative to bouncing.

Do shocks on the truck alleviate chucking? - No. The truck’s suspension is designed to quell vertical motions, chucking is fore and aft. Chucking forces will be felt in the cab independent of the truck’s suspension.

Does the hitch cause chucking? - No. The chucking forces are created by the trailer. Most hitches just transmit those forces very effectively to the truck. Some hitches with loose kingpin connections make noise due to chucking forces. A hitch with a tighter hook up will eliminate the noise but the trailer generated chucking forces will still be there.

Why don’t travel trailers chuck? - Their hitch ball is level with the rotational axis therefore the hitch angle is zero and all trailer generated forces are bouncing forces.

Durb

[Garyl53]

Rhagfo,
I am running 55 psi Front and this past trip I ran 65 psi rear. I have 295/70R18s. Here is the Load/Inflation table.

...................................35.... 40.... 45.... 50................... 55.... 60.... 65.... 70.... 75.... 80
LT295/70R18 Single .2295 2520 2735 3000 (C) 119 3150 3345 3525 3730 3910 4080 (E) 129

allen8106 -
Yes, I am rapidly comming to that conclusion. Question is what would I replace it with, a F350 DRW?

[allen8106]

Garyl53 wrote:
Answers for Old-Biscuit:

IS 5th wheel LEVEL when hitched to truck?
(Garyl53) Within 1" or so.

What air pressure are you running in air bags on truck?
(Garyl53) I have tried to be be just barely off the overloads (about 30# in bags) and I have also tried to level the truck which is about 1-2" off the overloads (about 50# in bags).

5th wheel has a dry weight of 9795# and dry pin weight of 2375# (24% pin weight)

What pin weight do you have with 5vr loaded up camp ready?
(Garyl53) about 2700#

Mor/Ryde RPB, Correct Track II, EZ-Flex Equalizer, Lippert Shock Kit on 5vr should provide SMOOTH towing

Issue with chucking could be stiff truck suspension (4X4 Camper/Plow/FX packages) and the wheel base of that F250

F250..10K GVWR
1683# cargo carrying capacity
14,400# max tow.........but you have run out of payload hence the air bags and rough riding

The label specs on my F250 are 10k GVWR, 14.4k max tow, 2020# payload, 23.5 GCWR, 6200# GRAWR. I also believe due to the options configuration it is identical to F350 with following specs:
11.5k GVWR
15.7k max tow
23.5k GCWR
3.5k payload

I think I am under all specs except labeled payload (2020# v 2720# actual)
Here are CAT numbers:
Truck only -
Steer - 4720#
Drive - 3300#
Total - 8020

Truck + 5vr -
Steer - 4840#
Drive - 6020#
5vr - 8680#
Total- 19540#

Thank you for the questions.

You've got a 2020 payload with a pin weight of 2700, therein lies your problem.

[rhagfo]

Garyl53 wrote:
Hi,
Here is an update from the OP:

I was able to locate some 5200 lb. front coil springs for a reasonable price so I removed the 6000 lb. plow package springs. This resulted in a slightly better unloaded ride but nothing significant. I just returned a camping weekend and I would say that the new front springs had the effect of making the "chucking" just slightly less severe. The "chucking" was still very much present but the amplitude or severity of the "push-pull" feeling was a little less. Unfortunately it will need to get a lot better or I will have to look into a new trailer and/or truck combo. I am planning on finding someone local to pull my 5th wheel just to see if they also experience the issue when using a different tow vehicle.
Again thanks for all of your suggestions and please post anymore ideas about this issue.

Gary, what air pressure are you running in the front tires? I don't run 80 psi in the fronts between 60 and 65 psi should be correct for the load they are carrying. You also might look at the load on the rear tires and drop the pressure to about 75 psi.

To all that say too much 5er for your F250, I carry and pull likely the same size 5er with my 2001 Ram 2500, I don't have bags just a tow and camper package, and a optional 265/75-16 E tire rated at 3,415# ea.

[Garyl53]

Hi,
Here is an update from the OP:

I was able to locate some 5200 lb. front coil springs for a reasonable price so I removed the 6000 lb. plow package springs. This resulted in a slightly better unloaded ride but nothing significant. I just returned a camping weekend and I would say that the new front springs had the effect of making the "chucking" just slightly less severe. The "chucking" was still very much present but the amplitude or severity of the "push-pull" feeling was a little less. Unfortunately it will need to get a lot better or I will have to look into a new trailer and/or truck combo. I am planning on finding someone local to pull my 5th wheel just to see if they also experience the issue when using a different tow vehicle.
Again thanks for all of your suggestions and please post anymore ideas about this issue.