How do I fix this?

[mrpopgun]

Hi everyone.

I'm a new Montana owner (3230ck) as well as a new Ram 3500 (SRW, Crew, 6'4" bed, Cummins HO and Aisin) owner. Andersen Ultimate hitch with the adapter block towards the cab to provide a little more room for the nose.

I came from a 35' tow behind and now have the 3230ck as my 1st fifth wheel. Guess I was expecting a HUGE difference in overall stability and ease of pulling. So far, well it isn't meeting expectations but I think it can be addressed.

Issue: Pulling down the road, any road, there is this constant back and forth push/pull down through the center of the truck from nose to tail. It really actually feels like a slight (but constant) misfire or like when you're running out of gas and there is that back and forth as you have power, lose it then regain, repeat. It doesn't feel like the porpoising I had when my WDH setup wasn't dialed in correctly or when tongue heavy for the suspension (fixed on my last truck with Sumo's).

What the heck is causing this? Only think I can think of is maybe I'm flexing the suspension just enough to feel sort of like a micro-porpoising? Trailer pivots on axles vertically at nose and tail. When nose goes down it's actually a down and back sort of angle and "pulls" the truck back. It then rises back to top dead center where the goose ball stops the motion in which case good ole equal and opposite reaction then forces it back down? Seems possible and crazy at the same time to me.

Any feedback on what might cause and more importantly FIX this issue? Didn't think I'd have any issues like this going with a 3500 and a trailer in this weight class. If it's a suspension thing am I simply looking at Sumo's, Timbrens or Bags to resolve?

Haven't made the time to do proper weighing, but here's what I have when running back from camping last weekend and running across the public scales.

Truck alone (different scale so I need to vet this)
Front: 4475lbs
Rear: 2575lbs

Truck with trailer attached
Truck Front: 5150
Truck Rear: 6700
Trailer: 11,350

Sticker info
Truck
GAWR Front: 6000
GAWR Rear: 7000
GVWR: 11,800 (I suppose this means I am 50lbs overweight?)
Combined weight occupants and cargo: 3718 (yellow sticker)

Trailer
Unloaded weight: 13,000
GVWR: 16,680
GAWR (each): 7000

[scottz]

Someone with an Anderson hitch might help out more; I know nothing about them. Your weights sound about right except the empty truck weights sound a little light. I had a similar truck except it was a long bed (F350 SRW diesel super cab) and it's empty weight was 5140/3600, total 8740. Your 5th wheel weight is the same as mine.

So, you know you are right at maximum for that truck; that is most likely the problem. Is this your first 5th wheel? You will experience a push/pull (chucking) from the trailer and it will increase the closer you are to your weight limits. I put air bags on my F350, ran them at about 40psi. That was just enough to stop most of the chucking; I was not trying to raise the truck height. Very happy with them.

Any time now, people are going to pop up and tell you to buy a bigger truck; DRW. That will probably solve the problem, but not what you asked. I pulled my Montana coast-to-coast and to Alaska several times with the F-350 SRW (more overweight than your truck; 1100 on the rear axle, 700 on each rear tire) and felt quite safe; until I got worried about the rear tires (not the truck); but that is a different story.

You have a new truck and probably do not want to trade it; especially now with inflated truck prices and shortages. You would probably be happy with a set of airbags to help out your suspension. I think that would solve your problem for about $400; a little less than buying a new $100k truck. I had the AirLift brand with onboard air and wireless remote on two trucks, happy with them.

Best of luck

PS: if you are not the DIY type, Henderson's Line Up in Grants Pass is a great shop; they can probably provide some sound advice. They do suspension work on all kinds of vehicles and trailers. https://www.hendersonslineup.com/

[rohrmann]

What you are experiencing is called chucking, and this is what happens with fifth wheels, where a travel trailer has the porpoising problem. We have a MORRyde pin box that has a rubber suspension in it that helps control this. Not sure what can be done with your pin box and hitch combination. What pin box do you have?

[mrpopgun]

Thank you both for the reply. Very helpful. I read "chucking" everywhere but I thought that was associated with traditional 5ver hitches and kingpins only and referring to the movement of the kingpin within the hitch capture mechanism. Ask and learn I suppose.

My king pin is the stock RoadArmour Trailair. They have some dampening in them, but with the Andersen you have to use lockout bolts to disable that dampening.

Sounds like I'm going to be installing some air bags or a set of Sumo's or Timbrens because I want this fixed. Super annoying and makes me tense while driving as well.

[JDDilly]

I have air bags on my truck. They do nothing for the chunking, at least what I can tell.

[DQDick]

At the last two actual Montana national rallies many folks swapped out that pinbox for a Morryde just to help with the problem you describe. I was the vendor coordinator at those rallies and was shocked at the number of folks trashing new rotoflex for a Morryde. Both of our Montanas have the Morryde and our 2010 did also, so I can only go by what I saw and was told.

[scottz]

I also have the Morryde pin box; it helps. I could definitely tell a difference when I put pressure in my air bags. Most notable on interstate expansion joints. Not sure how much the Morryde box is; you will have to decide which to try first; you may end up with both. Unfortunately it will be trial and error. If I was in Medford, we could hook my trailer up to your truck and see how it pulls. Come to the Coeur d'Alene rally and we'll work on this. There will be a ton of experience there.

https://www.montanaowners.com/forums...ad.php?t=82568

Still wondering about that Anderson hitch and having to disable your pin box dampening.

[RMcNeal]

I put Timbrens on my F350 last year. Took care of most of the porpoising I was experiencing on overpasses, bridges, etc. They really dampen the "noise" from the rig. I also have the stock Trailair pin box. I don't seem to have a chucking problem, but then I never noticed it before the Timbrens either. I have the B&W Companion hitch with the Ford puck system. Not an Anderson hitch, though.

[phillyg]

Seems like you're describing chucking, but I don't know anything about the Anderson hitch vis-a-vis your pinbox. All I can tell you is the Morryde pinbox dampening makes a night and day difference in reducing chucking used with my conventional hitch.

[twindman]

I had another thought on chucking. Maybe your trailer brakes are not adjusted correctly or the switch in the truck is not set high enough. If properly working, the trailer brakes should sort of drag back on the truck. If too weak, it may slam forward into the truck and sort of bounce forward and back. Something to think about, I guess.

[BB_TX]

When traveling down the highway and that highway has “imperfections”, when the truck crosses one of those it slightly slows the truck. And the trailer gives it a push. Then the trailer crosses that same place and it causes the trailer to slightly slow. And the trailer pulls back on the truck. Push/pull. That is chucking. Concrete highways are the worse for me as it seems those “imperfections” are repetitive due to the way they pour the concrete. Asphalt highways are generally far less troublesome, at least for me. The chucking cause (highway) is there no matter the hitch or pin box. It is just that some dampen it better than others.

I have an older Monte with a 5th Airborne air ride pin box that mostly eliminates the chucking. But still not all on concrete highways. No air bags, Timbrens, etc. Don’t know about any of the potential solutions above.

[432bartman]

I have and Anderson and have zero chucking. is your trailer sitting level on the truck? Is there any play with the Anderson hitch with it sitting on the factory gooseneck and not hooked to the trailer? Is there any play with the Anderson ball itself. Is everything torqued correct and tight? My Anderson is being used with a Curt gooseneck. Is there any loose hardware on your gooseneck? Trying to give you some areas to look at.

[mrpopgun]

So looks like I have some homework. Hopefully I can get out this weekend to do some testing.

1. Get to a level spot and check the level of the trailer when hooked up. At first I knew I was too high so I lowered the gooseball in the hitch 1 notch. Looks decent visually but I need to see what the level says.

2. I need to adjust my trailer brakes up gradually to see if that helps the problem or not. I'm at 6.5 right now (I suppose that doesn't matter as the needed setting is unique to all setups) so I'll go up by .5 at a time until it's obvious I'm over braking the trailer.

3. I need to do some measuring to see how much room I have nose to cab. Maybe I can spin the kingpin/goose adapter around to be more over the axle. Not sure I'll really have that option due to not being a long bed.

4. If those fail, I'll have to determine what I'm going to try 1st to help things out. SumoSprings, Timbrens air bags, Load lifters, upper overload bumpers...

[twindman]

Seems to me anything like air bags, etc would not help. They cushion the up and down bouncing and you are experiencing a forward/backward motion. I don't know if other hitches have any cushioning like needed, but the Moryde (?) has a sort of slide plate and a rubber cushion to dampen the forward backward movement. I added it at the Rally 2 or 3 years ago and it helped (maybe 60% less), but didn't eliminate the chucking.

[JandC]

When I pulled my two different Montana fivers with a SRW F350 (short box) I experienced some chucking back and forth. Since these fivers squatted my truck a little I added Firestone bags on the rear. Of course that did nothing for the back-and-forth movements, but it did level the truck nicely.

As long as everything else checks out, like your hitch is mounted securely, I would think the only thing to change what you have described is changing pin boxes on the fiver. One of the fancy air adjustable ones should help a bunch.

[ChaseTX]

I have an Anderson hitch and have towed roughly 2K with it. You should have zero chucking, coming from your hitch set up. It works just like a ball socket, there is not much room for back and forth. I as well tow with a ram 3500 SRW.

I agree with the above comments, take another look how level you are, if your truck is squatting and your camper is nosed is lower than the rear. This will create havoc.

[jeffba]

you may want to check your pinbox. Anderson requires lockout bars to be installed to keep the pinbox from flexing

[BobStack]

I would first look at your Pin box height and make sure your fifth wheel is sitting level. If your trailer is low or high in the front the transfer of load from axle to axle when you hit a bump will cause the problem. Start there first.

[MARK A]

Originally Posted by mrpopgun

Hi everyone.

I'm a new Montana owner (3230ck) as well as a new Ram 3500 (SRW, Crew, 6'4" bed, Cummins HO and Aisin) owner. Andersen Ultimate hitch with the adapter block towards the cab to provide a little more room for the nose.

I came from a 35' tow behind and now have the 3230ck as my 1st fifth wheel. Guess I was expecting a HUGE difference in overall stability and ease of pulling. So far, well it isn't meeting expectations but I think it can be addressed.

Issue: Pulling down the road, any road, there is this constant back and forth push/pull down through the center of the truck from nose to tail. It really actually feels like a slight (but constant) misfire or like when you're running out of gas and there is that back and forth as you have power, lose it then regain, repeat. It doesn't feel like the porpoising I had when my WDH setup wasn't dialed in correctly or when tongue heavy for the suspension (fixed on my last truck with Sumo's).

What the heck is causing this? Only think I can think of is maybe I'm flexing the suspension just enough to feel sort of like a micro-porpoising? Trailer pivots on axles vertically at nose and tail. When nose goes down it's actually a down and back sort of angle and "pulls" the truck back. It then rises back to top dead center where the goose ball stops the motion in which case good ole equal and opposite reaction then forces it back down? Seems possible and crazy at the same time to me.

Any feedback on what might cause and more importantly FIX this issue? Didn't think I'd have any issues like this going with a 3500 and a trailer in this weight class. If it's a suspension thing am I simply looking at Sumo's, Timbrens or Bags to resolve?

Haven't made the time to do proper weighing, but here's what I have when running back from camping last weekend and running across the public scales.

Truck alone (different scale so I need to vet this)
Front: 4475lbs
Rear: 2575lbs

Truck with trailer attached
Truck Front: 5150
Truck Rear: 6700
Trailer: 11,350

Sticker info
Truck
GAWR Front: 6000
GAWR Rear: 7000
GVWR: 11,800 (I suppose this means I am 50lbs overweight?)
Combined weight occupants and cargo: 3718 (yellow sticker)

Trailer
Unloaded weight: 13,000
GVWR: 16,680
GAWR (each): 7000

I've never used anything but the B&W Companion, all I can add, is 6'8" bed Ford F350 I can put an open coffee cup on the dash and it won't slosh out. But hitting a bump all bets are off! LOL



Mark

[MARK A]

Originally Posted by twindman

I had another thought on chucking. Maybe your trailer brakes are not adjusted correctly or the switch in the truck is not set high enough. If properly working, the trailer brakes should sort of drag back on the truck. If too weak, it may slam forward into the truck and sort of bounce forward and back. Something to think about, I guess.

You don't want your trailer brakes dragging without applying the brakes, that's a recipe for disaster.


Mark