Chucking - trouble shooting

[dkuntz]

I’ve found a few strings in the forum on this topic. I’ve come to the point where I’ve concluded there isn’t a silver bullet to resolve the issue unless I want to spend several thousand on a TrailSaver hitch in the truck - which only eliminates the feel of the chucking, not necessarily the chucking. That being said, I’m looking for advice on where to start the process of elimination to first minimize the chucking coming from the trailer, and then the steps to minimize the impact at the truck.
1) Fill the trailer/truck so its loaded similar to how I will be camping and use that as a baseline for the chucking.
2) Add equalizers/shocks to the leaf springs on the trailer
3) Upgrade the factory king pin on the 5W to a MorRyde type rubber pin box
4) If that doesn’t eliminate 95% of the chucking on the truck, then I may have to look at getting an air system hitch on the truck.

For those that will ask; I have a 2019 2500 Duramax, pulling a 2020 5W Keystone Cougar 1/2 ton 29MBS. I’m within all charts/weights/etc. King Ping weight is 1,700lbs. Tire pressures are as spec’d (even though I don’t agree with the people on the forums that this matters with chucking). I added B&W gooseneck hitch to the truck frame and bought the Andersen Ultimate hitch in the truck bed along with the locking plate to the king pin box. The trailer has a front bedroom, middle bunk house, and kitchen in the rear. Cougar has stock “Road Armor” suspension system on the axles. I’ve only towed it so far completely empty from the dealer and to the storage facility. The chucking was miserable.

[Lightning55]

Second Chance wrote:
Chucking is a function of interaction(s) between the truck and the trailer and is highly influenced by the road surface. There are solutions FAR less expensive than $2,000 air-ride hitches. One of the best solutions is the MORryde dampened pin box which runs between $400 and $600 depending on which model (weight rating) you need and where you buy it. A similar pin box fixed our chucking issues completely.

Rob

Well put. I installed the MorRyde pin box and it made a huge difference. It does not correct the chucking, it simply dampens and absorbs the jerking motion enough that you can live with it. It was the best $400 that I've spent on this trailer.

[allen8106]

In my opinion chucking is inevitable and nothing you can do will stop it. You may dampen the effects of the chucking but you won't stop it. In my experience chucking exists as a by product of two things: how you have the rig loaded and the road conditions. It's a known fact that an improperly loaded TT will have so much sway it can be dangerous. 5th wheels are no different in loading. A light front will cause chucking. I think the primary issue causing chucking is road conditions. Some roads cause chucking and some don't. When we travel cross country I tend to have a heavily loaded front end due to all the extra stuff I carry in case of an emergency. My set up rarely chucks but when it does it's obvious there's a change in road conditions that causes it. My biggest complaint is bridge transitions, they suck bad and cause chucking. No way around it no matter what you do.

[Cummins12V98]

Brace your foot on the hump that will help keep your foot solid.

[ivbinconned]

I think if your pulling a trailer that’s 10’000 plus in dry weight adding fluid or weight by any other means would have very little effect on way or the other.
The fact that a “tune” on my truck dramatically started the chucking and a tweaking of the tune made it go away makes me suspicious that the “drive by wire” technology in modern trucks may contribute to chucking.
I pulled lots with carb vehicles and never heard of or experienced chucking.
When my truck was chucking it would do it on everyone of my 3 trailers. 34 foot Cedar Creek with trailair, 28 foot goose cargo with 7 K axels and a 28 foot goose flat deck.
The key info here is that I could make it start, and stop, chucking with just The slightest pressure or lack of, on the pedal. Almost indiscernible. But it was this fact that made me ask the tuner,EFI Live, to Try some changes. They did
It worked. My truck never chucks.
Now this is my conclusion. Because of the modern technology that controls the accelerators in modern trucks I believe a stock truck may well chuck. Factory settings may well not take into account towing dynamics that can vary widely.
It may be possible that we can not feel our foot slightly pulsing on the pedal when the truck starts chucking but no doubt the truck picks up the signal and we contribute to the motion without realizing it.
Just my thoughts.

[laknox]

dkuntz wrote:
I’ve found a few strings in the forum on this topic. I’ve come to the point where I’ve concluded there isn’t a silver bullet to resolve the issue unless I want to spend several thousand on a TrailSaver hitch in the truck - which only eliminates the feel of the chucking, not necessarily the chucking. That being said, I’m looking for advice on where to start the process of elimination to first minimize the chucking coming from the trailer, and then the steps to minimize the impact at the truck.
1) Fill the trailer/truck so its loaded similar to how I will be camping and use that as a baseline for the chucking.
2) Add equalizers/shocks to the leaf springs on the trailer
3) Upgrade the factory king pin on the 5W to a MorRyde type rubber pin box
4) If that doesn’t eliminate 95% of the chucking on the truck, then I may have to look at getting an air system hitch on the truck.

For those that will ask; I have a 2019 2500 Duramax, pulling a 2020 5W Keystone Cougar 1/2 ton 29MBS. I’m within all charts/weights/etc. King Ping weight is 1,700lbs. Tire pressures are as spec’d (even though I don’t agree with the people on the forums that this matters with chucking). I added B&W gooseneck hitch to the truck frame and bought the Andersen Ultimate hitch in the truck bed along with the locking plate to the king pin box. The trailer has a front bedroom, middle bunk house, and kitchen in the rear. Cougar has stock “Road Armor” suspension system on the axles. I’ve only towed it so far completely empty from the dealer and to the storage facility. The chucking was miserable.

1) Make sure you're towing level.
2) Quick 'n dirty way to weigh down your FW is to simply fill all the holding tanks, then drive 40-50 miles on various roads to see how it handles.

A lot of what you're feeling is simply trailer bounce, especially if you don't have shocks, because you're empty. I know that when I bought my KZ and drove it home from the dealer, about 70 miles, it wasn't a real comfortable trip. After I loaded it up with stuff, even the little we normally carry (no more than 500 lbs, mostly in the front storage), it rode some better. When we went to our annual family boondocker, it towed =really= nice with 61 gallons of fresh water in the tank.

I know that, if we are ever to take a =long= road trip, like thousands of miles, I'd seriously consider adding the Joy Rider shock system, at minimum, or their Liberty Rider spring/shock package. The Liberty Rider changes the standard springs to "slipper" springs, where there's only one end of the springs that's bolted on; the other end is free to "slip", giving more play to the spring. I know that our 30' GN trailer has triple axles with slipper springs and it rides pretty darn nice, even empty.

Lyle

[ivbinconned]

Trail Air pin box on trailer and air bags on the truck. That would be my approach.

[dkuntz]

ivbinconned wrote:
At the risk of sending this thread off on a rabbit trail I have a question.
Does your truck have a performance “tune”?

No tune. Factory.

[dkuntz]

TxGearhead wrote:
Andersen Ultimate hitch in the truck bed along with the locking plate to the king pin box.
^^Explain this a little more. Do you have a RotoFlex that has to be locked out, or a conventional Morryde with a rubber shear spring? I don't think the shear spring model needs to be locked out for a Andersen or PullLite hitch. But I may not be understanding what you're saying.
That aside, I would load up and get the pin weight up, get the truck on the overloads, go to a CAT scale, determine if it's still chucking, then get closer to your tire and axle limits, but not over.

Rotoflex - per Andersen they have to be locked out from being able to rotate.

[ivbinconned]

The reasons I ask about a “tune” in the truck is because that became the source of my chucking in a long box 2016 Ram.
I came to the conclusion it was the truck because no matter which of my 3 fifth wheel trailers(cargo and flat deck and Cedar Creek) I towed it would chuck.
One should not assume it’s a hitch or trailer weight.
My tune was an EFI live tune. With the first version...no chucking. With the 2nd alternative one immediately I noticed the chucking. When the installer re-installed the tune with slight changes in the mapping...smooth sailing.
Hook your trailer onto some other trailers to confirm it’s not a truck issue.
I would also suggest you look at my post about trailer shocks.
If you have them the way they are mounted may make them useless and in fact be causing a ride issue with the trailer.

[CarnationSailor]

I am towing a 36 foot 5th with my 2500 HD short bed, TrailAir Tri-Glide pin box and Demco auto slide hitch. I get no chucking except for the occasional severely uneven highway seam/joint. Also, my 5th is 3 inches high in the front. Good luck.

[Thermoguy]

Thank you for posting this question. I have a 2015 Silverado 2500HD and had a similar experience when I purchased our 5th wheel. We have been towing a 3 horse gooseneck with no issues, then got the 5th wheel and wow, what an awful tow. I honestly think it is the short bed of the 2500 that causes the chucking especially with the larger trailer. Your's is much longer than mine so probably much worst. I looked at the Anderson hitch for the light weight and ease of taking it in and out of the truck but want to try one before buying. My concern is the lack of positions it can be moved to. I believe you can move it up and down but not forward and back. I might be wrong, but that is what it looked like to me.

I have the B&W companion and at first I put it as far back as possible and tried to level the trailer with the positioning of the hitch. That was awful for the chucking. During a trip to Yellowstone, every night I moved the hitch to find a better position for the best ride. I had to move it forward quite a bit and my trailer is not perfectly level but not bad. I also found that if my fresh water tank is full, it rides better. Probably pulling some weight off the hitch. It is definitely a balancing act as it is not perfect, but I would guess it is the trade off of having a short bed and short wheelbase truck.

Good Luck, I'm sure you can find the balance without buying a lot of hardware to mask the chucking.

[CarnationSailor]

dkuntz wrote:

mapguy wrote:


A third thing is concerning the factory overload engagement. IS it staying fully engaged or fully disengaged? If spring is bouncing off overloads -the ride suffers greatly

Good luck!

I don’t know what this is or I’m not understanding what you’re referring to. Thanks.

My 2015 Silverado HD 2500 did not come with overload springs. GM put overloads only on the 3500 that year. I have to wonder if they put overloads on your 2019.

[ivbinconned]

At the risk of sending this thread off on a rabbit trail I have a question.
Does your truck have a performance “tune”?

[TxGearhead]

Andersen Ultimate hitch in the truck bed along with the locking plate to the king pin box.
^^Explain this a little more. Do you have a RotoFlex that has to be locked out, or a conventional Morryde with a rubber shear spring? I don't think the shear spring model needs to be locked out for a Andersen or PullLite hitch. But I may not be understanding what you're saying.
That aside, I would load up and get the pin weight up, get the truck on the overloads, go to a CAT scale, determine if it's still chucking, then get closer to your tire and axle limits, but not over.