Crazy Surging

[Bespectacled Ape]

Towing a 10k RV with Max Tow (10k) and extended batt. Have chain-style WDH. Tires are all pressured up etc etc. Cruise is off.

Starts surging when I hit a rolling bump. Not doing more than 55 mph. Feels like it is a brake controller software issue but I have turned the sensitivity all the way down and it does not improve. Could feel like a surge brake oscillation but I don't have surge brakes. Hitch moves a little in the receiver but I don't hear any sharp knocking like that would be the problem. Surge is far too big for it to be just the hitch anyway.

My best guess (judging from the sloppiness of Ford's programming and lag of the onboard computer) is that the truck is sensing a sudden forward or rearward motion and electronically reducing throttle input, resulting in a harmonic resonance (oscillation).

BTW surging is a straight forward and straight back motion, and it is extreme enough to do damage. Experienced advice would be appreciated.

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[Grumpy2]

Hitch moves a little in the receiver

I suggest you may have a weight distribution issue. How much weight are you loading into the truck thru the WDH? Have you adjusted the WDH to see how the truck responds to the bumps?

 

[Hammick]

I towed a NuCamp Avia travel trailer from Louisville to Kansas City with a properly adjusted Anderson WDH and it was super smooth even over the crappy Indiana interstates. I'm guessing your hitch needs proper adjustment or your trailer brakes have an issue.

 

[Bespectacled Ape]

Not really sure I understand. The Lightning is fairly well balanced due to the batteries, and I don't have much weight in it. Other than a little bit of propane and the batteries, the trailer is almost stock toward the front end. There is ample weight on the tongue though. I run with water/sewage tanks empty.

I used the same WDH with the same trailer with a different tow vehicle and no surging. The WDH is tight and it would be difficult for anyone to put more tension on it. It supplies force vertically but I don't see how it could create a surge (forward/backward). The Lightning does not squat in the back much, the trailer is fairly level, and (open scissor-type) bouncing seems fairly restrained.

I get an immediate rearward push when I hit a rolling bump, like the nose of the Lightning is diving into the pavement. Steering gets loose very rarely during a bounce, like the trailer is fairly well balanced.

I suppose it could be the stock All-Season tires, and 6 plys would do better, but this really seems like a software issue. Somebody with an F150 must have seen this too.

 

[Bespectacled Ape]

I towed a NuCamp Avia travel trailer from Louisville to Kansas City with a properly adjusted Anderson WDH and it was super smooth even over the crappy Indiana interstates. I'm guessing your hitch needs proper adjustment or your trailer brakes have an issue.

Thx. How heavy is your trailer?

 

[Hammick]

Thx. How heavy is your trailer?

It's about 5,200 lbs dry so I was probably pulling 6,500 lbs. I can't say enough good things about those Anderson hitches. Super easy to use and adjust. I'll never use the snap up bars or chains again.

 

[Firn]

What effect does applying the trailer brakes through the controller have?

 

[LazyElectrons]

Are you in tow mode? Is 1 pedal driving on? I have experienced a surging issue when using 1-pedal driving with my 30’ travel trailer.

 

[RickLightning]

Bingo

 

[Bespectacled Ape]

What effect does applying the trailer brakes through the controller have?

Haven't really tried that. Pretty scary to do while it's surging. I can get the surging to die down by dropping speed, but I'd be doing that constantly on some patches of road.

 

[Bespectacled Ape]

Are you in tow mode? Is 1 pedal driving on? I have experienced a surging issue when using 1-pedal driving with my 30’ travel trailer.

Nah I don't like 1 pedal. It would be super hard to keep a steady throttle with all that surging.

 

[Grumpy2]

The Lightning is fairly well balanced due to the batteries, and I don't have much weight in it.

I think this is your problem. The truck is a beast, and it needs the load on it to operate well, I suggest you tighten/loosed the hitch and experiment more.

The driving characteristics will change significantly. I assume your trailer has about 1000lbs hitch load at least for it to handle well. The WDH can be used to level the truck and trailer on the road and help handling by pushing some of the hitch weight to the front axle.

The hitch should NEVER move within the receiver when the WDH is properly adjusted, especially with a 5 ton trailer.

You are near the load limits of the Ford recommendations, but it shouldn't be a problem as long as you have the needed tongue weight, and the WDH adjusted.

 

[SpaceEVDriver]

With a 10k lb trailer, you're talking either two or three axles. If you don't have the WDH height and angle adjusted correctly–so that everything is level on level ground in all three axes–then you'll be putting more weight on one of the axles when you shouldn't be. And whenever you shift that weight through a bump, sudden change in speed, etc, you can get oscillations in the entire rig suspension. This can feel like forward-backward motion if you're not used to it.

The WDH must have both its height and its ball-to-frame angle adjusted properly for the specific trailer and tow vehicle combination. And it must have its tension bars/chains properly aligned both to level ground and to the frame of the tow vehicle. It's unsafe to take a WDH that's been set up with one tow vehicle + trailer combination and use it with another without properly readjusting it. I have owned multiple WDHs because it's just safer and easier than trying to re-adjust every time I switch trailers or tow vehicles. There are instructions specific to your hitch and you should follow those instructions because each design is different enough to warrant a re-read of the instructions.

 

[RickLightning]

To properly adjust a wdh is a process that involves measuring and weighing. Ideally, you weigh the truck, and the truck with the trailer unloaded, then adjust the hitch and reweigh, showing the movement of weight from the rear axle to the front axle and to the trailer, all while verifying the height change of the front of the truck.

Improper adjusted wdh are common, as are using a wdh that is below the needed capacity.

 

[Bespectacled Ape]

I towed a NuCamp Avia travel trailer from Louisville to Kansas City with a properly adjusted Anderson WDH and it was super smooth even over the crappy Indiana interstates. I'm guessing your hitch needs proper adjustment or your trailer brakes have an issue.

Sounds good but I tried the Andersen website and there were several pages that were 404. Did they get sued?

Also, there were several positive reviews on YT, but they were not for 5T trailers, and many said they wouldn't trust it. Has anyone seen one on my size trailer?

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