sway control

[towpro]

in my trailer tow section of Sync screen there is a switch for auto sway control. When this is on, IF the truck does something to react to something it saw as "sway" does it display any kind of warning light?

truck is a 2023 F150 with the large cab and the short 5 foot something bed with 20" tires.

the reason I ask:
I started a trip with my new 2022 Jayco 26' (model 21mml) camper. I was using a Reese weight distribution hitch with the bars and chains and a curt friction sway bar. UP above maybe 55mph the truck would take more effort to control steering. It was worse when you were in a situation where a large truck was too close following you or how they pass you and they like to switch lanes back to in front of you with only 1 or 2 car lengths of space.

I don't think this is "sway" as I can remember my Dad years ago getting passed by a big truck and the trailer started to wag like the tail on a dog and only applying trailer brakes would straighten it out), that is the sway I recall.

First thing I did was tighten up the chains on the weight distro hitch by one link. That really did not make a difference.
Next I bumped the rear tires up to 40psi, maybe it made a little difference.

I have been towing 5th wheels for the last 30 years (accept for my 7x14 box trailer but I have not towed it since I got rid of my last dually) . In fact the weight distro hitch I am using is based on some original parts from the hitch dad switched to 50 years ago.

so on this long trip I saw a camping world and stopped by to look at new weight distribution hitches.
I wrote down what they had and researched them, then the next morning went back and purchased the Curt TruTrack 4P system.

I had to continue the trip another 500 miles until I got to my brothers where we installed the new hitch.
We feel the new hitch is setup correct, it certainly seems to straighten out some of the problems I was having pulling with the old hitch, but it’s not 100% perfect. Truck still seems to need active steering input to run at or above 65mph.

at the next camping stop on the trip, I thought about the fact the trailer had 65PSI in the load range D tires, which the inflation charts indicate would be good for 2000 lbs. each (4 tires) but crossing a cat scale shows the RV only has 5300 lbs. total weight on the tires, or 1325 lbs. each tire. inflation chart shows the PSI for 1430 lbs. should be 30psi . but no way I am going to go down to 30psi in one step. So, I pull out my tire gauge, and it only goes up to 50psi . I let out some air but I think I am still above 55psi. but it made some difference. (I am home now, but I will continue to test the effects of trailer tire PSI on this problem, just not sure how low to go. most of my travel is on roads marked at 70mph. while I don't go 70, it helps to go 65 to not get run over.

Next, I tried turning off the "sway control" button on the truck trailer tow screen. Wow, it seems to make a big difference with this busy steering at higher speeds. But I swear I read in the manual that if the auto sway control does anything, it turns on a warning light? is this difference with switch off my imagination?

any guidance from the group?
Here is the Tire inflation charts. Its the top tire in the list ST205/75R14 D
what PSI would you run?

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[Davexxxx]

Interested in the replies you get.

I'm just familiar enough with the loading chart, to know it exists but haven't strayed from stamped max cold, or tire sticker on the trailer.

I also haven't turned off sway control but am curious about that. I've seen where some claim it can be beneficial to turn it off, depending on the hitch, trailer combo.

It does seem that mine is a little twitchy and if that is the truck doing that, as in a constant, overcorrection, I'd be happy to be shed of it. Might improve towing mileage as well.

 

[powerboatr]

I can say from towing long time
I have never seen a light in any of my current or former ford's

However it does make a difference with it selected on vice off as you have stated
I would think if was a severe enough 3vent you may see a warning or hear a chime.

You did great, checking tires pressures and loading , tongue etc
They all contribute to safe towing or unsafe towing

 

[Ricksc]

When I tow I run the truck tires are 50psi. Same on trailer. Leaving sway on. I did upgrade rear shocks and front coil overs and my last trip towed great. Seems the shocks and coil overs were the biggest help.

 

[cghall77]

Have a 29ft trailer and keep the tires at the pressure listed on the yellow sticker same as the truck. I did install Timbrens and upgraded to Equal-i-zer hitch took a little while to get dialed in, but it does run very smooth. I have played with the sway control and don't notice any difference nor have I ever seen a light come on.

 

[Aron]

To answer your question about a warning if the system gets triggered, I believe that the answer is "yes it does" (though I'm not 100% sure). I haven't had it trigger on my F150 while towing yet, but on my 2015 Expedition I once had a "trailer sway warning--anti-sway system engaging" message pop up when I was going a bit too fast down a windy road through Pennsylvania. I have to assume that if the anti-sway technology back in 2015 included a visual warning, that the same technology in 2024 would also warn you that it's being triggered.

It sounds like you're not experiencing sway as much as you're feeling like the trailer is continually pushing you around a bit. My experience is that the lane-keeping system sometimes does this while towing at higher speeds, especially if there's some cross winds involved. It makes it feel like you're always fighting the steering wheel to keep in control because the wind is pushing you towards one lane edge, and the system is constantly trying to correct for that. The feeling (to me at least) is unnerving because you don't know if the wheel is moving because the technology is trying to keep you centered, or if the wheel is moving because the trailer is starting to sway. My recommendation is that if you start getting this steering wheel pushback, turn off the lane-keeping system (if you have it) rather than the anti-sway system. That seems to work best for me, at least.

 

[towpro]

great replies.

I Think I had the lane assist turned off, but I do use the cruse control all the time towing (for the auto speed adjust, living in Central Florida that is nice with all the built in speed traps).

I leave the radar turned with Cruse and adjust the following distance all the time, this helps me adjust my speed to a truck I may be following but keeps me far enough away to stay out of the trucks wind disturbance.

I really do have a feeling that the trailer is moving around (blowing around or bouncing around) because with over inflated tires the contact patch is too small and it starts to move around.

I guess this is about the shortest bed truck I have ever towed with @ 145". My last truck I did much towing with was 24" longer wheel base.

 

[Buyer2021]

The dread "sway" is a continuing oscillation with increasing amplitude, distinctly different from the momentary displacement of a wind-gust or passing big-rig that quickly abates with a properly set-up rig.

Most any rig will feel the latter in certain circumstances, and that's no cause of concern or untoward reaction / correction.

The former is a very undesirable and dangerous propensity which 99% of the time is due to lack of sufficient forward weight bias (aka 'tongue weight') in the trailer assuming all other things are good (i.e. tire pressures, trailer level, etc). If your rig is on the margin of that propensity, an external force such as a wind-gust or passing big-rig can initiate the dread "sway".

With any luck Ford's trailer sway-sensing systems can distinguish between the two different situations and not over-react to the latter. Nope, I've never thought about trying to set-up situations to 'test' that.

IME tongue weight of at least 12% of total loaded trailer weight (measured with WDH not engaged) is your best friend, then use the WDH to 'correct' for the resulting vehicle sag as needed.

Just for your consideration, Have Fun!

 

[Skier167]

I did find this video showing our newer gen trucks from ford so I would agree with @Aron that it will alert you when the trailer sway control kicks in. I have turned mine off in the past and did find out it will turn back on automatically every time you stop/start the truck again. I did ask in the Forscan thread on turning it off permanently and got a response but I haven’t had time to try out the changes yet.

 

[towpro]

Have a 29ft trailer and keep the tires at the pressure listed on the yellow sticker

On every RV I have owned, if you take the carrying capacity of the 4 tires, PLUS the tung weight, you would find the GVWR of that trailer. But this Jayco is not that way, I assume only because they don't sell tires with that low of a carrying capacity.

 

[Buyer2021]

On every RV I have owned, if you take the carrying capacity of the 4 tires, PLUS the tung weight, you would find the GVWR of that trailer. But this Jayco is not that way, I assume only because they don't sell tires with that low of a carrying capacity.

Interesting, my experience with many trailers, RV and otherwise, differs.

In my observation, just like cars & trucks, the maximum OE tire capacity displayed on the sidewall always exceeds the vehicle / trailer placard GVWR / GTWR (and the individual axle WRs).

The placard GTWR is a function of the trailer's chassis and suspension capacity / design limits. We (or at least I) would hope that the OE tire capacity provides a comfortable safety-margin above that. IME it always does.

 

[Pdugan2816]

21’ Tremor 3.5 eco. I tow 7k camper with a ProPride hitch. Max cold tire pressure setting on camper and I forget it’s back there….. ProPride is pricey but it doesn’t REDUCE sway..IT ELIMINATES IT!!! Traveling up and down the east coast through wind ,rain, big trucks, 70mph speed limit and mountains. Heading out West in a couple months and never second guessed my purchase. Back to the question in hand. I have never had a sway warning or light or any kinds of steering or sway issue. But then again, this is the only hitch I have used besides 5th wheel.

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