328M 5er odd swaying

[Old_BANE]

Thank you all for the quick responses. The Alt Trailer Height is a factory function of the air suspension. It lowers the rear to help level the trailer. The pictures are with the function engaged/suspension lowered. So if I return it to default height it will make the trailer even more nose high.

Again, this is all with an empty garage. The motorcycle I put back there is 440# plus tools probably puts me around 500# cargo in the garage.

So now with the empty garage I’m at 20%, I’m going to try adding water to get that number higher.


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[geotex1]

This is actually pretty basic. You do not have enough weight on the pin. On flat level ground, the pin weight is acting vertically with gravity. As you climb an incline, the force still acts in the direction of gravity, but the component of the weight now acting normal, or aligned with the hitch, is reducing. This is why forces are vectors, and have directional components. You need more weight on the pin, and that weight should be contributed as closely as possible to the pin. So, in the front storage, bedroom closest, etc. Moreover, some toyhaulers are more finicky than others because of where their center of gravity is with toy and then without. The greater the variation between the two, the harder it is to get a comfortable tow at all times.

[Hoopy Frood]

That all sounds very logical, but doesn't explain why it tows better when there is weight in the garage, which would take even more weight off the pin. That's the big question.

FWIW, our old triple axle toyhauler pulled better when the garage was loaded. And there was an even 20% on the pin.

[geotex1]

That all sounds very logical, but doesn't explain why it tows better when there is weight in the garage, which would take even more weight off the pin. That's the big question.

No, it does, but I realize the forum is not full of engineers or folks that love physics. With the toy in the garage, it's changing where the TH's center of gravity is. Everyone has come to understand the basic teeter-totter with running gear centerline as a fulcrum, which is great. However, that's gravity load in static conditions on level ground. Not so simple running down the road. Sure, it all can be solved with mathematical models, but in the real world of every day it's sometimes more clear to simply guide folks by telling them how to get to the solution versus how to analyze it.

[A.Texas.Yankee]

Have you tried towing with the auto level disengaged? The 2500 with air ride and the springs in the back get a little wonky with shifting weight loads while traveling. That could explain your issues up hills because your pin weight is going to change and your leveling system will try to accommodate. As much as I loved my '19 2500 Longhorn with the air ride, it was great with bumper pulls only for me. Anytime I had the gooseneck trailer on and loaded with the front loader, it just never rode the same. I didn't have much sway, though, but I didn't run a 5th wheel on my 2500 either. Lots of RAM owners over at HD Rams had issues with anything over 1500 lbs pin on the air suspension and general concensus was about 2k lbs being the comfortable limit for the auto level.

Full Timing Family
2021 Momentum 395MS-R
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[Hoopy Frood]

In your first post you said: "This is actually pretty basic. You do not have enough weight on the pin." and "You need more weight on the pin, and that weight should be contributed as closely as possible to the pin."

How does removing more weight from the pin by adding toys to the garage contribute to less sway, if he needs more weight. Please keep it simple for us dolts.

[Always Learning]

TV: 2016 Ram 2500 CCLB Laramie with the air suspension, towed at the Alt Trailer Height, Superglide hitch with the picture frame adapter for the Ram puck system, tires at 65psi front, 80 psi rear per sticker

I do not want to start the truck debate since there are many threads that cover that topic, have you considered that your problem may be caused by your truck. Your truck should be about maxed out. Do you know anyone with a different truck to tow your trailer to see if they have the same problem? If they do have the same problem then you can concentrate on the trailer. If the sway problem is caused by the truck then trying to correct the problem by changing things in the trailer may not produce the desired results.

You also mention that you have the picture frame adapter for the Ram puck system. Is there any possibility that is contributing to the problem?

[geotex1]

In your first post you said: "This is actually pretty basic. You do not have enough weight on the pin." and "You need more weight on the pin, and that weight should be contributed as closely as possible to the pin."

How does removing more weight from the pin by adding toys to the garage contribute to less sway, if he needs more weight. Please keep it simple for us dolts.

Sway in not just generated by one aspect. With a toy in the garage he stated it is better, not no sway, but better. Better is because the mass in the garage now move the effective center of gravity lower. The lower the center of gravity, the more stable. The OP is trying to get a balanced experience but he is also trying to accommodate little to no freeboard in payload. So probably will never achieve complete comfort that is desired, but by shifting weight depending how they are camping that trip will make a huge difference. Getting some 40-50# sacks of sand or weights from the home gym and some trial and error will figure out how much more is needed to make the difference in feel, and then the OP will have to come to terms with the payload.

[Hoopy Frood]

Thank you for the continued explanation. He may have issues with adding more weight though, since from what I can tell, he is at, or over, his GVWR for the trailer. He said he is at 20% pin weight at 2920 lbs. and a GVWR of 14, 400 lbs. And that is without the motorcycle in the garage. It looks like he's about 1,000 lbs. over his GVWR.

I'm not a member of the weight police, but one does have to wonder if he may expecting a bit too much from the 3/4 ton truck. IMO, 15,000 lbs. is getting pretty much into dually territory.

[roegs01]

.....The 2500 with air ride and the springs in the back get a little wonky with shifting weight loads while traveling. That could explain your issues up hills because your pin weight is going to change and your leveling system will try to accommodate. As much as I loved my '19 2500 Longhorn with the air ride, it was great with bumper pulls only for me. Anytime I had the gooseneck trailer on and loaded with the front loader, it just never rode the same. I didn't have much sway, though, but I didn't run a 5th wheel on my 2500 either. Lots of RAM owners over at HD Rams had issues with anything over 1500 lbs pin on the air suspension and general concensus was about 2k lbs being the comfortable limit for the auto level....

I'm new to this group, but am active on the HD RAM's forum and as Texas Yankee mentioned above this has been discussed as a concern with the 2500 air suspension. I believe part of the discussion was the air suspension bags being mounted further inboard (toward the center of the truck axle) than leafs for other trucks such as the RAM 3500. The end result was less side to side stability. I didn't do all the math on the OP's original post, but his pin weight seems to be pretty high for a 2500 truck. Couple that kind of pin weight with the uniqueness of the 2500 air suspension and things could get a little dicey. I run a similar pin weight with my 2930RL and RAM 3500 with rear air assist and its very stable towing. The air on the 3500 is a totally different setup though and uses traditional air bags with a lighter duty leaf spring pack. In that case, the bags simply assist a traditional leaf spring setup.