How much sway is expected and normal ?

PeterInNH

Senior Member
Joined
May 13, 2024
Messages
100
Location
Southern NH
Hi All,

Just recently I picked up my new Momentum 28G from the dealer - the spec sheet says it came in at 9428lbs. To this point I've added nothing so if there's a difference (say the single battery) it has to be relatively minor. My tow vehicle is a 2024 F350 with a payload capacity of 4160lb, around 18k towing and +2k lbs hitch weight - all should be well within limits, correct ? The dealer installed what seems a very beefy Blueox Swaypro. Also, for those who know this truck, I did turn off the software based Ford sway control.

Anyway, on my way home that first day we had some very high predicted wind gusts, over 40mph, and I was knocked around pretty good at times but I just chalked it up as "well, don't travel on days like that in the future". lol

However, yesterday I made a quick trip back to the dealer and encountered a few instances where (no wind to speak of) the trailer seemed to waggle around all on its own - not enough to push me out of my lane but definitely enough to give me a decent shock. While it did happen at other times it was especially noticeable when being overtaken by big semis - before the head of the truck passed directly beside me it was almost like my trailer was being pushed around by an air pressure 'bow wave' from the semi.

So, my questions are:
Is this normal ?
Do I have not enough/too much tongue weight ?
Is there some adjustment to be made to the Blueox ?
Should I try towing without the bars (and rely on the Ford software) ?
Do I have the wrong truck ? (hope not !! lol)

Thanks for any help !

Peter
 
The "bow wave" from semis is normal, but if you feel like you're being pushed off the road, that isn't normal to me. My fifth wheel doesn't get pushed much or at all by semis. My old bumper pull did have quite a bit of sway when I was pulling with a half-ton truck, not so much when I upgraded to a three-quarter-ton. I'm unfamiliar with your hitch, but I'm guessing some adjustments might help.
 
No sway, EVER is the expected and normal.
But let's define terms. True sway is where the trailer oscillates from side to side (tail wag), sometimes building to the point where it throws the TV and trailer off the road! It is due to not enough tongue weight and the speed at which you are traveling. Observe the trailer in your side mirrors - if the back end peeks out in one mirror, then switches out to the other mirror, you have the beginnings of sway, and a potentially very dangerous condition. Minimum tongue weight should be 12% of the current weight of the trailer.

BUT - there are a lot of other things that people call "sway" that really aren't - they are usually one at a time occurrences. Truck suck and wind pushes fall into that category.
Make sure you aren't getting true sway. Get to a truck scale and weigh everything to make sure your tongue weight is good. Make sure the trailer when hitched up is either level or a slight bit nose down. Make sure your WDH is adjusted to be less than Ford's recommended front fender rise in a towing situation. Some advise to restore all the weight to the front - increase WD to see where it makes a difference for you.

The bars only serve to distribute weight front to back on the truck. Disabling the Ford anti-sway defeats a big safety feature. Use both the bars and the anti-sway.
 
While it did happen at other times it was especially noticeable when being overtaken by big semis - before the head of the truck passed directly beside me it was almost like my trailer was being pushed around by an air pressure 'bow wave' from the semi.
The 'bow wave' is definitely noticeable. But I found 'truck suck' to be more disturbing. Both are normal. Just be ready for it. Like when I'm passing a semi, I'm prepared to turn away from the truck as soon as the 'suck' starts.
 
The "bow wave" from semis is normal, but if you feel like you're being pushed off the road, that isn't normal to me. My fifth wheel doesn't get pushed much or at all by semis. My old bumper pull did have quite a bit of sway when I was pulling with a half-ton truck, not so much when I upgraded to a three-quarter-ton. I'm unfamiliar with your hitch, but I'm guessing some adjustments might help.
Yes, yesterday wasn't anything close to the 40mph gusts I experienced prior and I never felt like I was going to go out of my lane/off the road.

Maybe a call to the dealer and talk to the tech who set up the Swaypro is in order.

Thanks !
 
No sway, EVER is the expected and normal.
But let's define terms. True sway is where the trailer oscillates from side to side (tail wag), sometimes building to the point where it throws the TV and trailer off the road! It is due to not enough tongue weight and the speed at which you are traveling. Observe the trailer in your side mirrors - if the back end peeks out in one mirror, then switches out to the other mirror, you have the beginnings of sway, and a potentially very dangerous condition. Minimum tongue weight should be 12% of the current weight of the trailer.

BUT - there are a lot of other things that people call "sway" that really aren't - they are usually one at a time occurrences. Truck suck and wind pushes fall into that category.
Make sure you aren't getting true sway. Get to a truck scale and weigh everything to make sure your tongue weight is good. Make sure the trailer when hitched up is either level or a slight bit nose down. Make sure your WDH is adjusted to be less than Ford's recommended front fender rise in a towing situation. Some advise to restore all the weight to the front - increase WD to see where it makes a difference for you.

The bars only serve to distribute weight front to back on the truck. Disabling the Ford anti-sway defeats a big safety feature. Use both the bars and the anti-sway.
Ok, yes, I described it as more of a 'waggle' - where the trailer rear end, without a doubt, did do some oscillation (but entirely within my lane). It was easily corrected - basically by easing up on the gas a tiny bit and letting the semi go on his way.

The hitch weight according to the factory specs is about 1368lbs and, since everyone seems to think that is much lower than reality, I would think that's in the ballpark for the 9428lbs trailer weight as it left the factory.... ? Regardless, getting to a weigh station is definitely on my to-do list.

As far as the Ford software/system - I've read many times in various Super Duty forums that using it at the same time as a physical device such as the Swaypro basically sets up a (potentially) dangerous reverse feedback mechanism where the two systems basically fight each other for control and either ends up with neither doing its job or making the situation worse.

Thanks !
 
The 'bow wave' is definitely noticeable. But I found 'truck suck' to be more disturbing. Both are normal. Just be ready for it. Like when I'm passing a semi, I'm prepared to turn away from the truck as soon as the 'suck' starts.
'Truck suck' ! Very descriptive (and accurate).

By the end of 40mi ride home I was doing a much better job of looking out for passing semis (I did very little passing of anything on my own). It's just something that I have to learn to be more vigilant about (I can see why I read so much about folks limiting their travel days to 300mi, or less - totally exhausting !).

Thanks !
 
Looks like the OP has about 14.5% tongue weight on that trailer, which is good. Once "toys" are added to the garage, then that number will come down some, but I would not think below 10%. Also, since the garage extends way into the living area, it would be best to get the load over the trailer wheels if possible.

On my 2017 F350, the maximum load of the hitch is 1500 lbs with a WDH. Not sure what the 2024's are, but the OP should check that out.

The Sway Pro is a good hitch made in the USA, but there might be better choices out there for sway control, especially for that long of a trailer. Wandering Weekends on YouTube does a great video on WDHs, and he did not rate the Sway Pro very high. He even rates the Blue Ox TrackPro as a better option, as well as about 1/2 dozen other units.

Also, the OP needs to make sure the spring bars are appropriately sized.

The hitch needs to be set up correctly. With Super Duties, Ford recommends that front wheel measurements be taken with no trailer, and then with the trailer attached with no spring bars in place. With the spring bars in place, then the front fender well measurement should fall about 1/2 way between the 1st 2 measurements.

The trailer fuel tank appears to be in the back of the trailer. I would recommend that either be empty, or as full as practical to not cause the sloshing fuel to affect the sway. That also goes for fresh and waster water tanks, especially if behind the axles.

I tow a 26' travel trailer with my 2017 F350, and there is very little to no sway. If a tractor trailer passes at high rate of speed, then I can feel the bow wave if too close to the center line. If I am paying attention (which I should be), I move over to the outside line a bit, and can't feel the wave near as much.

And like the OP, I try to remember to turn off the trailer sway control when towing. It is something about using that with a WDH that just doesn't work out well. I can definitely tell when I forget to do that, and regretfully, the trailer sway control can not be turned on and off while driving, and has to be done every time the truck is started.
 
Ok, yes, I described it as more of a 'waggle' - where the trailer rear end, without a doubt, did do some oscillation (but entirely within my lane). It was easily corrected - basically by easing up on the gas a tiny bit and letting the semi go on his way.

The hitch weight according to the factory specs is about 1368lbs and, since everyone seems to think that is much lower than reality, I would think that's in the ballpark for the 9428lbs trailer weight as it left the factory.... ? Regardless, getting to a weigh station is definitely on my to-do list.

As far as the Ford software/system - I've read many times in various Super Duty forums that using it at the same time as a physical device such as the Swaypro basically sets up a (potentially) dangerous reverse feedback mechanism where the two systems basically fight each other for control and either ends up with neither doing its job or making the situation worse.

Thanks !
The best way to stop sway is to manually activate the trailer brakes while keeping the throttle steady,
Think of a rope being pulled on both ends...It will be straight...Practice this so you can do it without looking at the controler. It will save your bacon if a big sway event occurs.
 
Looks like the OP has about 14.5% tongue weight on that trailer, which is good. Once "toys" are added to the garage, then that number will come down some, but I would not think below 10%. Also, since the garage extends way into the living area, it would be best to get the load over the trailer wheels if possible.

On my 2017 F350, the maximum load of the hitch is 1500 lbs with a WDH. Not sure what the 2024's are, but the OP should check that out.

The Sway Pro is a good hitch made in the USA, but there might be better choices out there for sway control, especially for that long of a trailer. Wandering Weekends on YouTube does a great video on WDHs, and he did not rate the Sway Pro very high. He even rates the Blue Ox TrackPro as a better option, as well as about 1/2 dozen other units.

Also, the OP needs to make sure the spring bars are appropriately sized.

The hitch needs to be set up correctly. With Super Duties, Ford recommends that front wheel measurements be taken with no trailer, and then with the trailer attached with no spring bars in place. With the spring bars in place, then the front fender well measurement should fall about 1/2 way between the 1st 2 measurements.

The trailer fuel tank appears to be in the back of the trailer. I would recommend that either be empty, or as full as practical to not cause the sloshing fuel to affect the sway. That also goes for fresh and waster water tanks, especially if behind the axles.

I tow a 26' travel trailer with my 2017 F350, and there is very little to no sway. If a tractor trailer passes at high rate of speed, then I can feel the bow wave if too close to the center line. If I am paying attention (which I should be), I move over to the outside line a bit, and can't feel the wave near as much.

And like the OP, I try to remember to turn off the trailer sway control when towing. It is something about using that with a WDH that just doesn't work out well. I can definitely tell when I forget to do that, and regretfully, the trailer sway control can not be turned on and off while driving, and has to be done every time the truck is started.
Thanks for great info !

My "toy" is my 650lb motorcycle and I've already planned on rolling it up and over the axles as close to possible. So, hopefully the effect will be minimal. Also, in the future will have tons of stuff stored in the camper front of the axles. I'll also be upgrading the battery to 2 larger LiFePo batteries and maybe even 2 30gal propane so will have more weight in the front to balance the rearward load for sure. The waste tanks are in front of the axles so will keep that in mid as well.

I have a memory of reading somewhere that the max hitch weight was 2k lbs (or higher) but in searching I cannot find it. But, I went for the F350 over an F250 'assuming' it could pretty much safely tow anything I bought. Hope that was right ! ;-)

I will have a chat with the dealer (and the tech) who installed the Swaypro but don't see me swapping to another brand for a while (too many other things will take priority). However, the Blueox web site indicates the Swaypro is needed if my trailer approaches it GVWR of 13k lbs. Maybe the bars need to be upgraded ? Will check. I'm also considering trying a test ride without the bars and with the Ford Trailer Sway Control turned on - this is a pretty big truck so it kight handle it no problem.

I haven't noticed any nose rise on my truck when hitched up - looks very level to me but I will do those measurements asap.

I will keep in mind the suggestion to travel with as little fuel and freshwater as possible. However, I'm hoping to do a significant amount of boondocking so we'll play that one by ear. Maybe 'fill up' closer to my destination...

As I said in reply to another response I've already learned that I need to be on alert more than I had to be when I was towing my boat. Lesson learned.

Thanks again for the helpful response !
 
Just to add a thought, with all of the above considered, I’m thinking you will find that the ride will improve a great deal once you have your trailer loaded. Empty rigs are (IMHO) more susceptible to the issues you are currently experiencing.
 
Thanks for great info !

My "toy" is my 650lb motorcycle and I've already planned on rolling it up and over the axles as close to possible. So, hopefully the effect will be minimal. Also, in the future will have tons of stuff stored in the camper front of the axles. I'll also be upgrading the battery to 2 larger LiFePo batteries and maybe even 2 30gal propane so will have more weight in the front to balance the rearward load for sure. The waste tanks are in front of the axles so will keep that in mid as well.

I have a memory of reading somewhere that the max hitch weight was 2k lbs (or higher) but in searching I cannot find it. But, I went for the F350 over an F250 'assuming' it could pretty much safely tow anything I bought. Hope that was right ! ;-)

I will have a chat with the dealer (and the tech) who installed the Swaypro but don't see me swapping to another brand for a while (too many other things will take priority). However, the Blueox web site indicates the Swaypro is needed if my trailer approaches it GVWR of 13k lbs. Maybe the bars need to be upgraded ? Will check. I'm also considering trying a test ride without the bars and with the Ford Trailer Sway Control turned on - this is a pretty big truck so it kight handle it no problem.

I haven't noticed any nose rise on my truck when hitched up - looks very level to me but I will do those measurements asap.

I will keep in mind the suggestion to travel with as little fuel and freshwater as possible. However, I'm hoping to do a significant amount of boondocking so we'll play that one by ear. Maybe 'fill up' closer to my destination...

As I said in reply to another response I've already learned that I need to be on alert more than I had to be when I was towing my boat. Lesson learned.

Thanks again for the helpful response !
MtnGuy is accurate in how Ford, at least in the past, recommended setting things and he clearly knows what he is doing. This is a reasonable place to start. Ask your dealer how it was setup.

I found it difficult and time consuming to adjust the 50% return because there is some stiction in the suspension and a small change can be significant. Also, many on this forum like to take camper and truck to CAT scale and measure weight on truck front axle wo trailer and then attach it and weigh again. The goal is to return front axle load to match axle weight wo trailer. More details are found on this forum. I resisted taking the easy CAT route for too long but after finally doing it found the stability was noticeably better. It is very clear where you are then.

Use the CAT app so you do not have to go in and pay. You will find that after you make weight changes later it is so easy to check where you are and make adjustments if needed.

You very likely will find the installed bars are too light to reach desired TV front return load. There are a range of optional spring bars from manufacture. If you do this soon you may be able to trade the current for the new. I would start with setting your link adjustments to maximum tension to start with when going to CAT. Expect your dealer to say you are doing it wrong...

Also, it is common for dealer to under torque the large bolt on hitch. If they measured torque, great but unlikely did (likely used an impact that is rated for x torque, which is way low with a loose joint). Use a wrench, with a long bar over it, on the nut with hitch rotated and apply enough weight (bathroom scale) at whatever distance that you are pressing, which provides desired torque (not written well but use force x distance= torque. If nut is not torqued enough it will loosen until nut falls off!
 
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Just as a reference point, I’ve driven 2019 and 2023 F150s towing an 8.5k lb 3100RD using the Blue Ox SwayPro with the truck’s antisway engaged. I have dialed in the hitch over the years such that the trailer and truck are level. I do not feel semitruck suck or push at all. I do feel slight effects from box trucks, tankers and car carriers, all creating different pressure wave profiles, but never enough to cause alarm. Keep your antisway on and work on your hitch adjustments. Happy towing!
 
The main goal of weight distribution/anti sway is not to level the truck. With an appropriately capable TV for the trailer, it often will level the truck. The reason I am highlighting this is I discourage adjusting weight distribution to level truck as this may detract from trucks stability and ride, and add confusion to proper setup. If truck does sag more than desired, making modifications to truck maybe appropriate, but check to see if rear axle and payload do not exceed trucks specs.

Using CAT scale and 100% weight return to front axle, mentioned above, also has benefit of taking load off rear axle and leveling truck. My 7200-pound (loaded) 24' TT 2019 F-350, Blue Ox SwayPro ended up with near 50% load on each front and rear axles (not the goal but nice). With proper weight return, front end alignment is correct, and headlights are not aiming incorrectly higher. Stability is excellent.
 
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I am using BXW1000 (10,000 rating) SwayPro Weight Distributing Hitch, with 1500-pound bars. You likely can get information from others with Momentum 28G, as to what spring bars they used with the 50% return method.
 
I always thought the front should get the bulk of the load (ahead of the axels). Or at least more weight should be ahead of the axels than behind them. But I am no load expert.

This might be a good example...????

It might be better to travel with less water/waste in the tanks too in order to prevent any sloshing which might exaggerate any sway.
 
PeterInNH, there is a sticker on your truck hitch that lists permissible weights. There should be 2 limits.......weight carrying and weight distributing.

TimtheToolMan hits on some great points:

A WDH should not be used to level the truck and trailer......that is a byproduct. The trailer should be leveled by the hitch height, with the WDH bringing the tongue up a bit more when used.

A trip to the CAT scales once you have done the fender measurements to get things close is a plus. 3 times across the scales (without changes to cargo, passengers, fuel) will give you all sorts of information. 1 time with the trailer and bars in place, 1 time with the trailer and bars not installed, and 1 time with truck alone. The difference between the solo truck weight and the trailer weight without bars will give you the true tongue weight. I drop my trailer in the lot to take get the truck solo weight. You might want to check with the weigh master to make sure that is OK, letting him understand it is only for a few minutes. The CAT scale app is great, but if you do multiple weigh ins, you need to go talk to the weigh master, as the CAT app would charge you the full price for each trip across the scales, instead of a dollar to so for the reweighs.

Do not rely on the dealer WDH setup !! I let the dealer setup my 1st WDH, and will never do that again. They had only about 40 lbs of weight put back on my front axle from ~300 lbs lost. I had to drill 2 more holes in my tongue frame because they installed the sway arm at the wrong position (Reese Straight Line Dual Cam), I worked about a year to get that bad boy dialed in correctly. My recent purchase I set up my WDH in the dealer lot, and I have tweaked the original setup since then to get it completely dialed in.

TimtheToolMan also mentioned making sure the WDH bolts are torqued correctly. An impact wrench is not a good way to torque bolts. A torque wrench is needed, or if no torque wrench is available, there are other methods to get the torque correct.

Doing the fender measurements: Make sure that you measure at the same spot each time. I put a piece of tape on my fender with a cross on it. I use a 4' level up against the vertical mark, and make sure it is plumb to the ground. My level has a ruler on the side, but you can use a tape measure beside of the level to do the same thing to the horizontal part of the cross marking.
 
I always thought the front should get the bulk of the load (ahead of the axels). Or at least more weight should be ahead of the axels than behind them. But I am no load expert.

This might be a good example...????

It might be better to travel with less water/waste in the tanks too in order to prevent any sloshing which might exaggerate any sway.
Your example is very good and interesting to watch.

When more weight is added to back of TT causing instability, it reduces load on hitch and TV rear axle but basically does not change load on front axle. The video may even have the trailer pulling up on hitch (TT rear weight bias). In this case the TV front to rear weight ratio actually increases but stability decreased. WDH does not change front to rear weight ratio of TT, but applies torque at the hitch, which applies load to TV front and TT axles and reduces weight on TV rear axle.

Added: As far as if it is better to have most of weight on front axle, in very general terms, I think it gets pretty complicated. I would say though that not returning weight on front axle also causes TV to lose some traction on front tires and possible turning safety in challenging conditions.

I have not attempted to understand the physics why having a proper TT F/R ratio increases stability, but we know it does. I too am no load expert.
 
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I am using BXW1000 (10,000 rating) SwayPro Weight Distributing Hitch, with 1500-pound bars. You likely can get information from others with Momentum 28G, as to what spring bars they used with the 50% return method.
Hi,

So, it looks like they gave me the same bars (4 dimples). I'm thinking that, when the trailer is fully loaded and anywhere near its 13k GVWR, I'll need the 5 dimple 2k bars. Might even help now since I'm only guessing at what the actual tongue weight is ?

Thoughts ?
 
I have a memory of reading somewhere that the max hitch weight was 2k lbs (or higher) but in searching I cannot find it. But, I went for the F350 over an F250 'assuming' it could pretty much safely tow anything I bought. Hope that was right ! ;-)
Just (re)found the towing specs guide and my F350 has a max tongue weight of 2500lbs. So, it should hardly notice this trailer (which seems to be the case).

Also contacted the Service Dept at my dealer and they told me that the Swaypro 2k bars were reserved for some other 'commercial' hitch. So, I contacted BlueOx and that's total bs - I can upgrade, on my own, the bars for around $250 and might just do that if can't get satisfaction from the dealer.

Thanks all for the additional input - the information you get from this forum is like drinking from a fire house but I'm working on it ! lol

P
 

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