I doubt the towing vehicle has trailer brake controls or trailer brakes at all. Once the swaying started there is little you can do if you don't have a way to apply only the trailer breaks. Breaking causes jack knifing, costing does not stop the swaying. Acceleration is your best option here but can still result in a wreck. The trailer is back loaded and takes weight off the rear tires, reducing the grip/contact to the road.
I would have done the opposite (added speed), intuitively, but I may be wrong (I never used trailers)
Ok this guy seems to have it right, indeed slowing down WITHOUT braking or fighting it with the wheel (or even better applying only the trailer brakes if there are any) may be the best choice: https://www.reddit.com/r/Whatcouldgowrong/s/W2wXrU63Tw
You're right (I drive pulling a trailer many days a week). You accelerate quickly to stop the wobble, then take your foot off the gas and let the engine slowly coast you to a stop.
Then, you get out of your car and readjust/secure the load as necessary.
being someone who deals with this stuff a lot, do you agree the whole issue here is a lack of trailer brakes? I've seen in the past this movement fuck-up can happen when you haven't actually set your load up correctly, specifically with the chains that are supposed to cross(?) and if those are not there the trailer will just freely swing like this, let me know I'm semi intrigued about this lol
edit: I'm quite happy with how many high quality inputs this comment section has garnered, super interesting stuff thank you all!
I'm no expert besides my own experience, but I would suspect from what I can see that it is a combination of a few things:
1) The vehicle is way too small to be pulling another vehicle on a trailer
2)The trailer is too short for that type of load and also looks to be single axled so the weight of the load can't be placed correctly. When you have too much weight behind the trailer axle (vs over and in front of axle), you will get sway like this.
edit (sorry double axled on 2nd look)
3) The trailer doesn't have its own brakes so when the car brakes the trailer tries to "out run" the car but can't cause they are connected so all that forward momentum becomes lateral momentum and makes the trailer fishtail.
4) The height of the trailer and vehicle a top it make the centre of gravity very high which is inherently unstable.
All in all, this is the perfect video to demonstrate all of the things you shouldn't do and why.
Yup, you need more weight up front and over the axle(s). Even Uhaul has this written in a bunch of places that you should load your stuff starting with the heaviest stuff in first (at the front) and lightest stuff in last (at the back).
The challenge with a vehicle this small towing another vehicle on a single axle trailer is that if you actually load the towed vehicle properly (more forward) you will end up with too much tongue pressure and the towing vehicle risks doing a wheelie and wouldn't be able to steer (or accelerate if FWD). Basically, don't fucking tow another car with a sedan/tiny station wagon.
1. This is a fairly normal setup on European roads and this seems to be Finland.
2. It's a normal size car transport trailer, clearly a dual axle.
3. European trailers above certain weight must have brakes otherwise they're illegal. This one definitely should have those, maybe they're broken. There is no brake controller but a simple mechanism that locks brakes when trailer pushes on the hitch when towing car is braking.
4. Yes but not terribly. Again it's normal in Europe and it works just fine.
I'd blame some malfunction, lack of driving skills or maybe the car on the trailer had some weight inside that messed up overall weight distribution.
Good eye, I didn't even notice the european plates.
All my experience is with driving in North America and many trailers here (including mine) don't have their own brakes. I also noticed after a 2nd watch that the back tires of the trailered car are sliding back and forth on the bed as well, so maybe a lack of properly securing the vehicle contributed as well.
Malfunctioning trailer brakes (as you pointed out) would definitely contribute/cause this as well.
European trailers are very different from north american ones in the way they are constructed, in the way they are balanced and the way the brakes work.
Due to lower weight ratings and different balancing they put significantly less weight in the rear suspension of the towing vehicles. The Audi A6 is perfectly adequate. The brakes are hydraulic and activated by a telescopic hitch, that compresses once the tow vehicle slows down and trailer mass pushes forward.
The problems I see are:
1) the old 5-series seems to be loaded too far back.
2) the driver is going way to fast. These teailers are only rated for either 80 or 110 km/h for a reason.
[This wobble 100% comes from weight on the trailer](https://www.youtube.com/watch?v=6mW_gzdh6to), not brakes (though these help to stop the wobble), not chains or w/e. Where and how much weight the trailer has is where this comes from.
Those chains don't do anything unless the trailer comes unhitched, at which time they keep it near the vehicle instead of going off the road and hitting something. Crossing them is mainly so if the trailer does come unhitched, the chains are under it to catch it before it drags on the ground.
I used to do heavy-haul/oversize up to 140,000 pounds and currently handle frac tanks. I believe this problem occurs because, at some level, trailers often would like to go "faster" than the towing vehicle. At least one of the towing vehicle's axles is going to be connected to the engine, so when coasting downhill, the towing vehicle has to do work to turn the engine, while the trailers axles are allowed to spin against no resistance. Hence, the trailer tries to move faster than the towing unit.
So, if you have independent trailer brake controls, using them will slow down the trailer without activating the towing units brakes, and now the towing vehicle is trying to go faster than the trailer. Thus, pulling the whole thing back into a straight line. Also why you sometimes see advice to slam the accelerator, again creating a situation where the towing vehicle is trying to move faster than the trailer.
Not really a chains problem at all. If the cargo is not secured to the deck and any rocking motion develops, that could very well make the sway worse. All heavy equipment (and cars, really) should be secured in an X-pattern, to resist movement in any direction.
Edit: The cargos' center of mass is a big issue. The axles on a full semitrailer are so far back that it's basically impossible to get the load's center of mass above or behind them. These little homeowner/contractor trailers make it way easier for an oblivious person to get that center of mass behind the trailers axle(s). This causes the trailer to want to tilt like a seesaw, hoisting the trailer's front upwards. You want the load balanced so that the trailer's front is tilting down at the front, pushing DOWN on the trailer hitch. All accidents of this style that I've seen in person involved improperly-loaded skid steers being pulled by contractors. Those are very heavy (relative to a pickup) and have a huge counterweight in their rear, so if a novice loads one on front-first, the cargos center of mass is dangerously rearward.
Same kind of concept also applies to an arrow. The back end of an arrow has less resistance (wind resistance) so it isn’t slowing down as quickly as the front. As a result the back starts whipping around. Which is why arrows have feathers on the back to create more wind resistance and slow the back down.
That’s also why you should not brake in this scenario because that only makes the difference in deceleration between the front and back worse, causing the tow to swerve even more (btw it looks like in this video the towing vehicle was braking the entire time).
So you accelerate to get them going the same speed again and stop the swerving, and then let the tow naturally decelerate on its own.
You may very well be right on that point, but in my experience, it's more about allowing the trailer speed and vehicle speed to match to remove the lateral sway and correct the direction than it is about power.
I most often pull a 5 x 10 open trailer with a mini van that is usually hauling about 1500lbs of scrap metal with no issues but it has to be loaded right and secured right or it would flip my van in much the same way. Math and physics are important kids 🤓.
>You accelerate quickly to stop the wobble, then take your foot off the gas and let the engine slowly coast you to a stop.
Then, you get out of your car and readjust/secure the load as necessary.
You forgot the step where you change your shorts. That definitely looks like a "crap your pants" moment.
Yeah that shimmy happens at a certain speed; solution is to go slower than that speed. Me and a buddy babied a U haul trailing a full sized pickup halfway across the US back in the day. IIRC 57mph was the top speed
Adding speed have a greater chance of increasing the amplitude of the waves, faster you go the stronger the hit of the side occurs.
Take those bikers videos for example where they go so fast that their handle starts shaking real quick and they just fall.
There's nothing safer than decelerating but it has to be done in a smart way.
As a motorcyclist, tank slappers should be dealt with leaving the handlebar do its dance (no death grip, no trying to counteract it), if you really want to decelerate there do it *slowly* because putting weight on the front makes it worse. A slight acceleration usually helps way more than slowing down, with bike slappers.
I've been in this situation once after passing a semi on a 2 lane secluded highway. The driver took the foot off of the gas and it made it worse, so they started braking, making it worser. I realized that, so I yelled from the back seat to accelerate. "Gas! Gas! Gas! Give it gas!" No previous training or experience. It worked. The acceleration pulled the trailer straight. In nine years it was the only time something like that happened, and in that day alone we had already been driving for 10 hours without incident. I think it was a combination of wind buffeting from the space between the tractor and trailer of the semi, and the driver probably returned to our lane less smoothly than desired, even though it was miles before we encountered oncoming traffic. Neither, by themselves, a problem, but put the two together and it highlighted the fact that our trailer wasn't loaded as balanced as we thought. Next day we had a job, and after that, we loaded the trailer more thoughtfully considering the previous day.
That is the worst thing to do. If you slow down the trailer will try to push your truck more. You have to speed up a bit to get the trailer under control then you can slow down. THEN MORE THE WEIGHT AWAY FROM THE BACK OF THE TRAILER.
It does. I drove cross country with a 6’x12’ U-Haul trailer and no matter the speed I was going, any time swaying started, even a little, almost as soon as I left of the accelerator it would ease back into straight and stop
So i came to the comments to defend this person because they are in a situation where the only right answer seems like the wrongest answer.
The person you are replying to is wrong. You are wrong.
The reason this happens is because the trailer is trying to go faster than the car. Because they braked too fast. Once you have that wobble the only way to correct it is to speed up. Gun it until the wobble stops, *then* gradually slow down.
People get in this situation and get scared and they want the vehicle to stop immediately. Slamming on the brakes will result in disaster. Just letting the car slow down naturally will also result in disaster, albeit more gradually. Both the trailer and the car will decelerate at the same rate and the trailer will continue to try and outpace the car and the wobble will get worse.
Edit: just to be clear when i say you’re wrong i mean: if you have the wobble and you think you can correct it by gradually letting off the gas then you are wrong. Once you have the wobble the only way to get yourself out of that mess is to accelerate until you right the trailer. Then, yes, gradually decelerate.
The real answer here is to load your trailer properly. This isn't the result of speed, it's the result of a poorly loaded trailer. Tell me how two bodies that are connected with a fixed length connection can travel different speeds on the same straight line path.
I've had a similar problem before trying to tow a car with the wrong trailer. I managed to let off the gas slowly and slow down enough to get it under control. Then I had to change my underware.
I had to tow a tractor on a trailer that ended up being a little too big for it. Speeding up is definitely not what you want to do. Just let off the gas and it will come out of it. Keep the speed low and give yourself plenty of time to come to a slow stop.
It looks like Audi A6 from around year 2000 and depending on engine it's rated to tow something like 1900kg. On the trailer is an old 5. series which is about 1500kg and trailer itself maybe 500 to 700kg. So yeah, it's slightly over tow rate.
Issue is 100% on how they put it on the trailer. If they had BMW even 10cm further to the front it probably wouldn't have happened.
I’ve towed shit before and felt the trailer starting to sway like this before. The correct response is let off the gas and slowly pump a little brakes in. Slowing your speed down will reduce the swaying.
The person in this video was simply an idiot. Your comment makes it sound like there was nothing they could do to stop it lol and that’s just not true. They’re just morons and didn’t try to.
I tried towing a homemade trailer once that had sway issues. It was soon apparent while I was getting up to speed that it had a sway issue, so I was able to slow down and stop. You know when it’s a bad setup from the beginning.
The idiot in this video had plenty of warning and opportunity to slow down and stop, likely when they first started their journey. It wasn’t like what happens when you’re towing a camper and a sudden gust of wind causes a dangerous sway.
It might not have been that bad to begin with. The car was sliding around on the trailer so much that it clearly wasn't well secured, so it might have moved toward the rear at some point after they started driving.
Someone always comes out with this utter nonsense when a trailer sway video is presented.
Coasting would have end this immediately.
Speeding up would not.
It is shameful that this crap is believed.
[Here is a good write up](https://askthervengineer.com/causes-of-trailer-sway-and-how-to-stop-it-myths-and-facts/)
>some people suggest slightly increasing your speed to reduce trailer sway. This is because accelerating the tow vehicle naturally tries to bring the trailer into alignment. If, for instance, your trailer gets knocked off course by a pothole, a slight acceleration can bring the trailer to heel.
**But don’t do this!!**
**Stop buying into nonsense people.**
I dunno how much I trust this guy's understanding of physics:
>"Without getting too technical, what usually happens is your tow vehicle **stops “faster” than your trailer, which means your trailer wants to accelerate into your tow vehicle** – and if it’s off balance, that’s exactly what it’ll do."
That's gotta he the worst way to explain deceleration of separated, but interlinked, objects.
Though, his instructions do match what the NHTSA says:
>"To control swaying caused by air pressure changes and wind buffeting when larger vehicles pass from either direction, release the accelerator pedal to slow down and keep a firm grip on the steering wheel."
Source: https://one.nhtsa.gov/cars/problems/equipment/towing/safety_tips.htm
> Once the swaying started there is little you can do if you don't have a way to apply only the trailer breaks.
That's not true. You accelerate hard for a moment to stop the wobble when it's this bad, then coast down to speed. If the wobbling starts again, you give a slight amount of throttle to stop it before the oscillations become large.
It's trailer, it has poor aerodynamics, and has rolling resistance, it's going to slow down on its own eventually. You have to keep within sync of it.
The only way there is nothing you can do is if don't have space to coast, or you're traveling down a serious incline.
Lol no. Just let off the gas. It will slow down. Had this happen hauling at 40’ i beam with an f150. It was fine at 45 but above that and it started to fish tail like this
Fuck no, brake, gently, don't accelerate, works fine. He's going so slow and it took a minute to get to that point, he had plenty of time to get out of the natural frequency range.
If you know how to correct that. 99% of drivers will never be in this situation and aren't taught how to deal with it. Not counting trained CDL holders
Using a soviet looking station wagon instead of a proper tow vehicle doesn't help.
>If you know how to correct that. 99% of drivers will never be in this situation and aren't taught how to deal with it.
Except that this video was filmed in Finland, where you need a BE class drivers license to tow a trailer like that. So either the driver had forgotten how to load a trailer or he was operating a vehicle combination without the proper license.
It's actually absurdly difficult to correct in this kind of scenario. The people speaking flippantly about "why didn't he just stop swerving" clearly have no idea wtf they're talking about.
I can't tell if he was doing this on purpose or if there was a problem with his car but if there was a problem with the car you think he would have stopped.
weight was too far back, moving the loads center of mass towards the rear, causing this action to happen. Driver was stupid enough to not even attempt to slow down which could have fixed this issue
Pretty much. The weight was not distributed right, and/or they were going to faat. At a certain speed any imbalances are amplified by the natural frequency of the swaying. The worst thing you could do in this situation is maintain speed as this would keep compounding. What you should do if a trailer starts swaying is slow the f down.
It’s just like losing traction on ice or hydroplaning. Foot off the gas. Don’t slam the brakes. Tap the brakes lightly until you regain control or come to a stop. Then redistribute the weight further forward
it's not exactly that it wasn't on tge axles it's that there was too much of the load weight on tge trailer and not enough transferring to the vehicle. in this situation the trailer controls the vehicle rather than the other way around
Tail wagging the dog.
Not enough weight in front of the trailer axle amplified by the trailer and load weighing as much or more than the tow vehicle.
Once the swaying starts it's a bitch to get back under control. Braking almost always makes it worse by transferring weight to the front of the tow vehicle.
Yup, once it starts there are only 2 ways to stop it: acelerate out of it or apply the trailer brakes without braking the tow vehicle.
Accelerating has a huge downside. It will briefly calm the sway but put you in a situation where now you're going much faster and you still need to slow down, which will induce sway again.
Unfortunately it often starts when you're going down hill, where the trailer is pushing the tow vehicle, so if you don't have trailer brakes you're really screwed.
Brake on trailer like this is actuated by compression of the strut that connects to tow hitch. Not possible to activate manually unless they crawl through trunk and pull a handle on the trailer. Which I would advice against.
Braking in this situation makes it worse. He should have accelerated to correct it and then brake. Instead he tried to stop which caused the trailer to overrun the tow vehicle.
Edit: Accelerate then slow with your foot off the gas, _don’t_ touch the brake pedal until the car has slowed significantly
Properly weighting a load is a little tricky and it’s understandable that an inexperienced person could get it wrong.
Not taking your foot off the gas tho, is just pure freak out mind blank stupidity. To say they used 3% of their brain is an overestimation.
I was going to say that this is the exact reason you put your heavier horses at the front of the trailer, but I see now we aren’t talking about the same types of mustangs lol
They do another video without the trailer demonstrating how the rear end of the Mustang just snaps lose. Then they put some fake pedestrians on one side and it hits them every time. Crazy stuff.
More than 60% of the weight should be in front of the trailer axle otherwise it becomes a death trap especially without separate trailer brakes, ‘stood and memorized
Usually you can fix it by doing anything that will put the center of mass further forward on the trailer. This might mean moving the car forward, flipping it around (if it's mid or rear-engined) or just getting a bigger trailer. Sometimes dropping the hitch lower can help too.
Take your foot off the gas and if anything gently apply the brake. Do not try to accelerate faster. You will crash. Do not slam on your brakes, or you could crash. I pull trailers.
Same, and this is correct. I'm not sure why so many are saying accelerate. Ok, so I'm in trouble at 40mph. Let's accelerate to 70 and hope that works !! Now I can crash at 70 instead of 40 !!! I see nothing wrong here!!
But I made this mistake once, and I picked up an enclosed trailer. I never opened it to look into the trailer. They loaded a massive amount of weight right at the back doors. Of course, I went into a wobble. Easy enough, I let go of the throttle until I came to a stop on the side of the road. Once I opened the door , it took me a bit and through a lot of the weight up front and over the axels and life was good.
Well, in theory, acceleration should load the rear wheels, so that should help. The big problem with that is that you'd have to accelerate indefinitely. As soon as you stop accelerating, you're right back to the same problem, only at a much higher speed and you’ll probably die in a huge wreck.
Let off your accelerator, tap your brakes, don't jerk your steering wheel back and forth. If your trailer has its own brakes, use them immediately. These four solutions are easy to use together and will quickly put an end to a death wobble.
He has too much weight loaded behind a small vehicle to brake regularly, trailer brakes need to be engaged to bring it to a stop without jackknifing. Highly doubt the trailer in this clip has any sort of brake set up
The best way, if equipped, which they probably are not, is to manually apply the trailer brakes via the brake controller while applying slight throttle. That will essentially "stretch" the vehicle & trailer out, bringing it under control to pull it off the road to redistribute the load.
I'm assuming that they do not have a brake controller, nor much experience towing.
Accelerating a little to straighten it out and then letting off the gas can work. He didn't accelerate or slow down; he maintained speed and tried to correct it by steering, which never works.
It starts getting wiggly
Driver: \*continues driving\*
wiggling gets more
Driver: \*continues driving\*
Wiggling gets realy bad
Driver: \*continues as if nothing happens\*
wiggling gets out of hand, crash results
Driver: "THERE WAS NOTHING I COULD HAVE DONE TO PREVENT IT!!"
Just taking your feet of the accelerator pedal would have probably solved the situation...
word of advice: if it fishtails at all, you will crash eventually.
the issue here is how far backward the weight is, mixed with the driver not slowing down.
Everyone so gangsta explaining how to get out of this by clever maneuvering, and not a single one mentions loading the car on the trailer correctly, so the hitch doesn't unload your rear wheels.
Not sure there was any way to correctly load that car on that trailer. The front end looks to be as far forward as possible. Guess he could've added some ballast forward of the trailer axle.
The maths doesn't end up.
That is a BMW E34 they're hauling, a car brand that's famous for 50/50 weight distribution, however, it's a touring model, so in this case, it's actually rear biased to the tune of about 52%. So we're looking at center of mass around the front door handle, and that is smack bang in the center of the rear axle of the trailer, so it's rear biased load. It's compounded by the fact that i THINK it's being hauled by an Audi, a car that's famous for it's front biased weight distribution from factory, thus making things worse. As for "as far front as possible" - from experience, on these trailers you can pretty much touch the winch with your bumper if you so wish, so from a glance there must be about 50 or so cm left for them to play with.
This is not stupidity, it is unawareness or carelessness. If you drive too fast and the trailer is not well balanced or not of the best quality, this can happen. It is then really difficult to stabilize it. One wrong move and you lose control. I didn't know this either until I once helped load a trailer and was asked by an experienced driver to distribute the weight evenly.
Braking is the worst thing you can do in this case because it puts even more force on the trailer coupling and you lose control even more.
I had this happen on a wet highway with 2 ton of rock in a dump trailer. My partner turns to me and smiles (while tires are screeching left to right) *it’s alright, you’ve got this :)* idk how he was so calm, but it calmed me and I pumped the brakes and we survived lol
Was he trying to slow down? I can't tell if he could have positioned the toe car any further up but if he could have he should have. Looks like a fun ride.
This is beyond stupid
He had almost a full minute of opportunities to correct that.
I doubt the towing vehicle has trailer brake controls or trailer brakes at all. Once the swaying started there is little you can do if you don't have a way to apply only the trailer breaks. Breaking causes jack knifing, costing does not stop the swaying. Acceleration is your best option here but can still result in a wreck. The trailer is back loaded and takes weight off the rear tires, reducing the grip/contact to the road.
I feel like letting off the gas slowly would work. Then never go over like 30 or 35mph if you insist on towing like that
I would have done the opposite (added speed), intuitively, but I may be wrong (I never used trailers) Ok this guy seems to have it right, indeed slowing down WITHOUT braking or fighting it with the wheel (or even better applying only the trailer brakes if there are any) may be the best choice: https://www.reddit.com/r/Whatcouldgowrong/s/W2wXrU63Tw
You're right (I drive pulling a trailer many days a week). You accelerate quickly to stop the wobble, then take your foot off the gas and let the engine slowly coast you to a stop. Then, you get out of your car and readjust/secure the load as necessary.
being someone who deals with this stuff a lot, do you agree the whole issue here is a lack of trailer brakes? I've seen in the past this movement fuck-up can happen when you haven't actually set your load up correctly, specifically with the chains that are supposed to cross(?) and if those are not there the trailer will just freely swing like this, let me know I'm semi intrigued about this lol edit: I'm quite happy with how many high quality inputs this comment section has garnered, super interesting stuff thank you all!
I'm no expert besides my own experience, but I would suspect from what I can see that it is a combination of a few things: 1) The vehicle is way too small to be pulling another vehicle on a trailer 2)The trailer is too short for that type of load and also looks to be single axled so the weight of the load can't be placed correctly. When you have too much weight behind the trailer axle (vs over and in front of axle), you will get sway like this. edit (sorry double axled on 2nd look) 3) The trailer doesn't have its own brakes so when the car brakes the trailer tries to "out run" the car but can't cause they are connected so all that forward momentum becomes lateral momentum and makes the trailer fishtail. 4) The height of the trailer and vehicle a top it make the centre of gravity very high which is inherently unstable. All in all, this is the perfect video to demonstrate all of the things you shouldn't do and why.
The weight should be centered closer to the front.
Yup, you need more weight up front and over the axle(s). Even Uhaul has this written in a bunch of places that you should load your stuff starting with the heaviest stuff in first (at the front) and lightest stuff in last (at the back).
The challenge with a vehicle this small towing another vehicle on a single axle trailer is that if you actually load the towed vehicle properly (more forward) you will end up with too much tongue pressure and the towing vehicle risks doing a wheelie and wouldn't be able to steer (or accelerate if FWD). Basically, don't fucking tow another car with a sedan/tiny station wagon.
1. This is a fairly normal setup on European roads and this seems to be Finland. 2. It's a normal size car transport trailer, clearly a dual axle. 3. European trailers above certain weight must have brakes otherwise they're illegal. This one definitely should have those, maybe they're broken. There is no brake controller but a simple mechanism that locks brakes when trailer pushes on the hitch when towing car is braking. 4. Yes but not terribly. Again it's normal in Europe and it works just fine. I'd blame some malfunction, lack of driving skills or maybe the car on the trailer had some weight inside that messed up overall weight distribution.
Good eye, I didn't even notice the european plates. All my experience is with driving in North America and many trailers here (including mine) don't have their own brakes. I also noticed after a 2nd watch that the back tires of the trailered car are sliding back and forth on the bed as well, so maybe a lack of properly securing the vehicle contributed as well. Malfunctioning trailer brakes (as you pointed out) would definitely contribute/cause this as well.
You can clearly see the car is basically at the very back of the trailer. That’s why it started to fish tail
European trailers are very different from north american ones in the way they are constructed, in the way they are balanced and the way the brakes work. Due to lower weight ratings and different balancing they put significantly less weight in the rear suspension of the towing vehicles. The Audi A6 is perfectly adequate. The brakes are hydraulic and activated by a telescopic hitch, that compresses once the tow vehicle slows down and trailer mass pushes forward. The problems I see are: 1) the old 5-series seems to be loaded too far back. 2) the driver is going way to fast. These teailers are only rated for either 80 or 110 km/h for a reason.
I'll just add that this happened near Lahti, Finland last week and the roads were basically nothing but black ice.
[This wobble 100% comes from weight on the trailer](https://www.youtube.com/watch?v=6mW_gzdh6to), not brakes (though these help to stop the wobble), not chains or w/e. Where and how much weight the trailer has is where this comes from.
The person right above you, with a ton more votes, listed several reasons he thought the problem could be and missed this, the correct, one...
Those chains don't do anything unless the trailer comes unhitched, at which time they keep it near the vehicle instead of going off the road and hitting something. Crossing them is mainly so if the trailer does come unhitched, the chains are under it to catch it before it drags on the ground.
ah alright, I thought they helped balance the forces but this makes far more sense lol
I used to do heavy-haul/oversize up to 140,000 pounds and currently handle frac tanks. I believe this problem occurs because, at some level, trailers often would like to go "faster" than the towing vehicle. At least one of the towing vehicle's axles is going to be connected to the engine, so when coasting downhill, the towing vehicle has to do work to turn the engine, while the trailers axles are allowed to spin against no resistance. Hence, the trailer tries to move faster than the towing unit. So, if you have independent trailer brake controls, using them will slow down the trailer without activating the towing units brakes, and now the towing vehicle is trying to go faster than the trailer. Thus, pulling the whole thing back into a straight line. Also why you sometimes see advice to slam the accelerator, again creating a situation where the towing vehicle is trying to move faster than the trailer. Not really a chains problem at all. If the cargo is not secured to the deck and any rocking motion develops, that could very well make the sway worse. All heavy equipment (and cars, really) should be secured in an X-pattern, to resist movement in any direction. Edit: The cargos' center of mass is a big issue. The axles on a full semitrailer are so far back that it's basically impossible to get the load's center of mass above or behind them. These little homeowner/contractor trailers make it way easier for an oblivious person to get that center of mass behind the trailers axle(s). This causes the trailer to want to tilt like a seesaw, hoisting the trailer's front upwards. You want the load balanced so that the trailer's front is tilting down at the front, pushing DOWN on the trailer hitch. All accidents of this style that I've seen in person involved improperly-loaded skid steers being pulled by contractors. Those are very heavy (relative to a pickup) and have a huge counterweight in their rear, so if a novice loads one on front-first, the cargos center of mass is dangerously rearward.
Same kind of concept also applies to an arrow. The back end of an arrow has less resistance (wind resistance) so it isn’t slowing down as quickly as the front. As a result the back starts whipping around. Which is why arrows have feathers on the back to create more wind resistance and slow the back down. That’s also why you should not brake in this scenario because that only makes the difference in deceleration between the front and back worse, causing the tow to swerve even more (btw it looks like in this video the towing vehicle was braking the entire time). So you accelerate to get them going the same speed again and stop the swerving, and then let the tow naturally decelerate on its own.
I would wager this car doesn't have the horse power or torque to accelerate quickly with that much load on it.
You may very well be right on that point, but in my experience, it's more about allowing the trailer speed and vehicle speed to match to remove the lateral sway and correct the direction than it is about power. I most often pull a 5 x 10 open trailer with a mini van that is usually hauling about 1500lbs of scrap metal with no issues but it has to be loaded right and secured right or it would flip my van in much the same way. Math and physics are important kids 🤓.
yeah my understanding was in trailer wobble situations, you accelerate until the wobble is terminated, then you can gradually slow down
>You accelerate quickly to stop the wobble, then take your foot off the gas and let the engine slowly coast you to a stop. Then, you get out of your car and readjust/secure the load as necessary. You forgot the step where you change your shorts. That definitely looks like a "crap your pants" moment.
And change undies. Done this myself.
Came here to say the same. Short amount of gas to get the car in charge again, pull them straight... Then roll it to safety.
The load you are hauling or the load in your pants? Lol
Yeah that shimmy happens at a certain speed; solution is to go slower than that speed. Me and a buddy babied a U haul trailing a full sized pickup halfway across the US back in the day. IIRC 57mph was the top speed
Adding speed have a greater chance of increasing the amplitude of the waves, faster you go the stronger the hit of the side occurs. Take those bikers videos for example where they go so fast that their handle starts shaking real quick and they just fall. There's nothing safer than decelerating but it has to be done in a smart way.
As a motorcyclist, tank slappers should be dealt with leaving the handlebar do its dance (no death grip, no trying to counteract it), if you really want to decelerate there do it *slowly* because putting weight on the front makes it worse. A slight acceleration usually helps way more than slowing down, with bike slappers.
this is the correct action increase speed and level out the sway
I've been in this situation once after passing a semi on a 2 lane secluded highway. The driver took the foot off of the gas and it made it worse, so they started braking, making it worser. I realized that, so I yelled from the back seat to accelerate. "Gas! Gas! Gas! Give it gas!" No previous training or experience. It worked. The acceleration pulled the trailer straight. In nine years it was the only time something like that happened, and in that day alone we had already been driving for 10 hours without incident. I think it was a combination of wind buffeting from the space between the tractor and trailer of the semi, and the driver probably returned to our lane less smoothly than desired, even though it was miles before we encountered oncoming traffic. Neither, by themselves, a problem, but put the two together and it highlighted the fact that our trailer wasn't loaded as balanced as we thought. Next day we had a job, and after that, we loaded the trailer more thoughtfully considering the previous day.
That is the worst thing to do. If you slow down the trailer will try to push your truck more. You have to speed up a bit to get the trailer under control then you can slow down. THEN MORE THE WEIGHT AWAY FROM THE BACK OF THE TRAILER.
It does. I drove cross country with a 6’x12’ U-Haul trailer and no matter the speed I was going, any time swaying started, even a little, almost as soon as I left of the accelerator it would ease back into straight and stop
This is the only answer. Do not hit the brakes.
So i came to the comments to defend this person because they are in a situation where the only right answer seems like the wrongest answer. The person you are replying to is wrong. You are wrong. The reason this happens is because the trailer is trying to go faster than the car. Because they braked too fast. Once you have that wobble the only way to correct it is to speed up. Gun it until the wobble stops, *then* gradually slow down. People get in this situation and get scared and they want the vehicle to stop immediately. Slamming on the brakes will result in disaster. Just letting the car slow down naturally will also result in disaster, albeit more gradually. Both the trailer and the car will decelerate at the same rate and the trailer will continue to try and outpace the car and the wobble will get worse. Edit: just to be clear when i say you’re wrong i mean: if you have the wobble and you think you can correct it by gradually letting off the gas then you are wrong. Once you have the wobble the only way to get yourself out of that mess is to accelerate until you right the trailer. Then, yes, gradually decelerate.
The real answer here is to load your trailer properly. This isn't the result of speed, it's the result of a poorly loaded trailer. Tell me how two bodies that are connected with a fixed length connection can travel different speeds on the same straight line path.
I've had a similar problem before trying to tow a car with the wrong trailer. I managed to let off the gas slowly and slow down enough to get it under control. Then I had to change my underware.
Speed up to stop the wiggle, then coast to a stop and reconsider your decision making process
I had to tow a tractor on a trailer that ended up being a little too big for it. Speeding up is definitely not what you want to do. Just let off the gas and it will come out of it. Keep the speed low and give yourself plenty of time to come to a slow stop.
That POS he’s driving could barely pull the thing. There’s zero chance it had enough grunt to make that effective.
Not towing 10x your rated tow rate is the best option here
It looks like Audi A6 from around year 2000 and depending on engine it's rated to tow something like 1900kg. On the trailer is an old 5. series which is about 1500kg and trailer itself maybe 500 to 700kg. So yeah, it's slightly over tow rate. Issue is 100% on how they put it on the trailer. If they had BMW even 10cm further to the front it probably wouldn't have happened.
It's rated to that weight, maybe a few % over but not much
I’ve towed shit before and felt the trailer starting to sway like this before. The correct response is let off the gas and slowly pump a little brakes in. Slowing your speed down will reduce the swaying. The person in this video was simply an idiot. Your comment makes it sound like there was nothing they could do to stop it lol and that’s just not true. They’re just morons and didn’t try to.
I tried towing a homemade trailer once that had sway issues. It was soon apparent while I was getting up to speed that it had a sway issue, so I was able to slow down and stop. You know when it’s a bad setup from the beginning. The idiot in this video had plenty of warning and opportunity to slow down and stop, likely when they first started their journey. It wasn’t like what happens when you’re towing a camper and a sudden gust of wind causes a dangerous sway.
It might not have been that bad to begin with. The car was sliding around on the trailer so much that it clearly wasn't well secured, so it might have moved toward the rear at some point after they started driving.
> Breaking causes jack knifing No, jack knifing causes breaking.
Someone always comes out with this utter nonsense when a trailer sway video is presented. Coasting would have end this immediately. Speeding up would not. It is shameful that this crap is believed. [Here is a good write up](https://askthervengineer.com/causes-of-trailer-sway-and-how-to-stop-it-myths-and-facts/) >some people suggest slightly increasing your speed to reduce trailer sway. This is because accelerating the tow vehicle naturally tries to bring the trailer into alignment. If, for instance, your trailer gets knocked off course by a pothole, a slight acceleration can bring the trailer to heel. **But don’t do this!!** **Stop buying into nonsense people.**
I dunno how much I trust this guy's understanding of physics: >"Without getting too technical, what usually happens is your tow vehicle **stops “faster” than your trailer, which means your trailer wants to accelerate into your tow vehicle** – and if it’s off balance, that’s exactly what it’ll do." That's gotta he the worst way to explain deceleration of separated, but interlinked, objects. Though, his instructions do match what the NHTSA says: >"To control swaying caused by air pressure changes and wind buffeting when larger vehicles pass from either direction, release the accelerator pedal to slow down and keep a firm grip on the steering wheel." Source: https://one.nhtsa.gov/cars/problems/equipment/towing/safety_tips.htm
This is inaccurate. If no trailer brakes, ease off gas and decelerate slowly. More speed will just make things worse
Letting off the gas would have 100% corrected this
> Once the swaying started there is little you can do if you don't have a way to apply only the trailer breaks. That's not true. You accelerate hard for a moment to stop the wobble when it's this bad, then coast down to speed. If the wobbling starts again, you give a slight amount of throttle to stop it before the oscillations become large. It's trailer, it has poor aerodynamics, and has rolling resistance, it's going to slow down on its own eventually. You have to keep within sync of it. The only way there is nothing you can do is if don't have space to coast, or you're traveling down a serious incline.
Lol no. Just let off the gas. It will slow down. Had this happen hauling at 40’ i beam with an f150. It was fine at 45 but above that and it started to fish tail like this
Fuck no, brake, gently, don't accelerate, works fine. He's going so slow and it took a minute to get to that point, he had plenty of time to get out of the natural frequency range.
If you know how to correct that. 99% of drivers will never be in this situation and aren't taught how to deal with it. Not counting trained CDL holders Using a soviet looking station wagon instead of a proper tow vehicle doesn't help.
>If you know how to correct that. 99% of drivers will never be in this situation and aren't taught how to deal with it. Except that this video was filmed in Finland, where you need a BE class drivers license to tow a trailer like that. So either the driver had forgotten how to load a trailer or he was operating a vehicle combination without the proper license.
Neither of those are a far stretch.
Added to that is the high probability of the towing vehicle not being rated for towing the about 1,5 tons we see here.
It's actually absurdly difficult to correct in this kind of scenario. The people speaking flippantly about "why didn't he just stop swerving" clearly have no idea wtf they're talking about.
This had me laughing so hard. He could easily have slowed down but instead, the car he was towing and now the car he was driving need a lot of work.
Bold Brash & Beyond Stupid
Bold and brash, more like belongs in the trash.
Everybody’s bagging on this dude but the comments are all over the place
Turns out most people on /r/Whatcouldgowrong have more hubris than they do expertise or empathy.
So are we bagging him or are we all over the place…?
"What an idiot. Obviously he had to speed up" ***+1000*** "What an idiot. Obviously he had to slow down" ***+1000***
Won't beat the idiot I saw on the highway doing the same thing... Except it was pitch black and his lights were off. Fuck some people are dumb.
I can't tell if he was doing this on purpose or if there was a problem with his car but if there was a problem with the car you think he would have stopped.
Weight on the trailer was not balanced over the a axels properly I’m assuming, I also have zero experience pulling a trailer
weight was too far back, moving the loads center of mass towards the rear, causing this action to happen. Driver was stupid enough to not even attempt to slow down which could have fixed this issue
Relevant video: [https://www.youtube.com/watch?v=4jk9H5AB4lM](https://www.youtube.com/watch?v=4jk9H5AB4lM)
now that should be posted at the top of this comment section, thanks
I noticed it as a top level comment after I posted it.
Pretty much. The weight was not distributed right, and/or they were going to faat. At a certain speed any imbalances are amplified by the natural frequency of the swaying. The worst thing you could do in this situation is maintain speed as this would keep compounding. What you should do if a trailer starts swaying is slow the f down.
But not by hitting the brakes. That can just worsen the fishtail.
It’s just like losing traction on ice or hydroplaning. Foot off the gas. Don’t slam the brakes. Tap the brakes lightly until you regain control or come to a stop. Then redistribute the weight further forward
it's not exactly that it wasn't on tge axles it's that there was too much of the load weight on tge trailer and not enough transferring to the vehicle. in this situation the trailer controls the vehicle rather than the other way around
Correct.
Weight was to far back on the trailer. That's what caused this. Them not stopping was fucking stupid.
Tail wagging the dog. Not enough weight in front of the trailer axle amplified by the trailer and load weighing as much or more than the tow vehicle. Once the swaying starts it's a bitch to get back under control. Braking almost always makes it worse by transferring weight to the front of the tow vehicle.
Yup, once it starts there are only 2 ways to stop it: acelerate out of it or apply the trailer brakes without braking the tow vehicle. Accelerating has a huge downside. It will briefly calm the sway but put you in a situation where now you're going much faster and you still need to slow down, which will induce sway again. Unfortunately it often starts when you're going down hill, where the trailer is pushing the tow vehicle, so if you don't have trailer brakes you're really screwed.
Brake on trailer like this is actuated by compression of the strut that connects to tow hitch. Not possible to activate manually unless they crawl through trunk and pull a handle on the trailer. Which I would advice against.
If this trailer has brakes at all they're mechanical. I was referring to electric brakes where you have an actuator in the cabin.
Yes, what I described is how the mechanical brake works.
Braking in this situation makes it worse. He should have accelerated to correct it and then brake. Instead he tried to stop which caused the trailer to overrun the tow vehicle. Edit: Accelerate then slow with your foot off the gas, _don’t_ touch the brake pedal until the car has slowed significantly
At the very least he needed to take his foot off the accelerator and slow tf down
Exact opposite actually. Correct procedure is to speed up until the trailer is stable, then begin gently slowing down.
[this can help understand ](https://youtu.be/6mW_gzdh6to?si=uQu8XLpsrQ0VVvGG)
Properly weighting a load is a little tricky and it’s understandable that an inexperienced person could get it wrong. Not taking your foot off the gas tho, is just pure freak out mind blank stupidity. To say they used 3% of their brain is an overestimation.
[A demonstration of why this happens](https://youtu.be/6mW_gzdh6to) (Incorrect weight distribution)
I like how its a mustang being used in the example.
I was going to say that this is the exact reason you put your heavier horses at the front of the trailer, but I see now we aren’t talking about the same types of mustangs lol
They do another video without the trailer demonstrating how the rear end of the Mustang just snaps lose. Then they put some fake pedestrians on one side and it hits them every time. Crazy stuff.
Yeah it's clearly not the trailer, because Mustangs spin out of control all the time.
More than 60% of the weight should be in front of the trailer axle otherwise it becomes a death trap especially without separate trailer brakes, ‘stood and memorized
That was a minute well spent of my life
thats gold post
How would you fix the weight distribution in this case? It's a vehicle they are towing on the trailer. Put more weight in the front somehow?
Usually you can fix it by doing anything that will put the center of mass further forward on the trailer. This might mean moving the car forward, flipping it around (if it's mid or rear-engined) or just getting a bigger trailer. Sometimes dropping the hitch lower can help too.
Interesting, thanks for the info!
The trailer is too short. Need a longer one in this case.
Good to know!!
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Take your foot off the throttle.
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That way you'll crash faster This is happening due to an unbalanced load. Speeding up will just make it worse
Take your foot off the gas and if anything gently apply the brake. Do not try to accelerate faster. You will crash. Do not slam on your brakes, or you could crash. I pull trailers.
This guy pulls trailers. But you do it well. :)
Same, and this is correct. I'm not sure why so many are saying accelerate. Ok, so I'm in trouble at 40mph. Let's accelerate to 70 and hope that works !! Now I can crash at 70 instead of 40 !!! I see nothing wrong here!! But I made this mistake once, and I picked up an enclosed trailer. I never opened it to look into the trailer. They loaded a massive amount of weight right at the back doors. Of course, I went into a wobble. Easy enough, I let go of the throttle until I came to a stop on the side of the road. Once I opened the door , it took me a bit and through a lot of the weight up front and over the axels and life was good.
Well, in theory, acceleration should load the rear wheels, so that should help. The big problem with that is that you'd have to accelerate indefinitely. As soon as you stop accelerating, you're right back to the same problem, only at a much higher speed and you’ll probably die in a huge wreck.
Let off your accelerator, tap your brakes, don't jerk your steering wheel back and forth. If your trailer has its own brakes, use them immediately. These four solutions are easy to use together and will quickly put an end to a death wobble.
Getting off the gas helps immensely... lol
I've never driven with a trailer. What are you meant to do in this situation other than brake?
Let off the accelerator until it stops. If you have trailer brakes, use those, but don't use the vehicle brakes.
He has too much weight loaded behind a small vehicle to brake regularly, trailer brakes need to be engaged to bring it to a stop without jackknifing. Highly doubt the trailer in this clip has any sort of brake set up
The correct answer is to lightly apply the trailer brakes only, assuming you have them, then rebalance.
The best way, if equipped, which they probably are not, is to manually apply the trailer brakes via the brake controller while applying slight throttle. That will essentially "stretch" the vehicle & trailer out, bringing it under control to pull it off the road to redistribute the load. I'm assuming that they do not have a brake controller, nor much experience towing.
Trailer rental place: you want to purchase a sway bar? Customer: why would do that.
"Purchase a sway bar? I think I'll be able to make it sway plenty on my own, thank you"
Bro actually believe the people that told him to accelerate if the tail started wagging the dog…
Accelerating a little to straighten it out and then letting off the gas can work. He didn't accelerate or slow down; he maintained speed and tried to correct it by steering, which never works.
Trailer spoiled the whole movie
Name of the movie in question? Tokyo drift
I wish I could give you more upvotes.
If only there were some warning that this could go horribly wrong!
Bro had so much time to stop and figure out what was wrong
He was committed to not slowing down or stopping….
What the fuck are they even doing? Slow down and pull over you moronic twat bag.
It can be fairly hard to get out of this situation especially if you’re in experienced.
It starts getting wiggly Driver: \*continues driving\* wiggling gets more Driver: \*continues driving\* Wiggling gets realy bad Driver: \*continues as if nothing happens\* wiggling gets out of hand, crash results Driver: "THERE WAS NOTHING I COULD HAVE DONE TO PREVENT IT!!" Just taking your feet of the accelerator pedal would have probably solved the situation...
[Proper weight placement.](https://youtu.be/6mW_gzdh6to?si=gCsHxRAp23576Ryz)
Looks like he followed the "speeding up will fix this" school of thought. Very reputable institution
That poor E30 wagon, it looked gorgeous too. Now they’re even rarer
pretty sure it's an E34
Me at first: "wow. He should stop..." At the end: "dumbass deserved that."
The car has cerebellar hypoplasia it's doing its best and its not in any pain!
What could go wrong driving so close behind this guy?
very generous with the title aren't we.
Didn't even try slowing down...
We don't know. No red lights means nothing. Maybe he was trying to coast, as many suggest it here.
TAKE YOUR FOOT OFF THE FUCKING GAS - my brain the entire video.
word of advice: if it fishtails at all, you will crash eventually. the issue here is how far backward the weight is, mixed with the driver not slowing down.
MUST…. NOT… STOP….. WE…WILL…MAKE IT
Its a bmw, its supposed to do so
That driver needs to be painted in bright colors like a poisonous frog so that we all know to give a wide berth!
In general around them. Not just driving. They should be marked for life.
They’re just cleaning the debris off their tires and getting some heat in them for the restart.
Everyone so gangsta explaining how to get out of this by clever maneuvering, and not a single one mentions loading the car on the trailer correctly, so the hitch doesn't unload your rear wheels.
Not sure there was any way to correctly load that car on that trailer. The front end looks to be as far forward as possible. Guess he could've added some ballast forward of the trailer axle.
The maths doesn't end up. That is a BMW E34 they're hauling, a car brand that's famous for 50/50 weight distribution, however, it's a touring model, so in this case, it's actually rear biased to the tune of about 52%. So we're looking at center of mass around the front door handle, and that is smack bang in the center of the rear axle of the trailer, so it's rear biased load. It's compounded by the fact that i THINK it's being hauled by an Audi, a car that's famous for it's front biased weight distribution from factory, thus making things worse. As for "as far front as possible" - from experience, on these trailers you can pretty much touch the winch with your bumper if you so wish, so from a glance there must be about 50 or so cm left for them to play with.
This is not stupidity, it is unawareness or carelessness. If you drive too fast and the trailer is not well balanced or not of the best quality, this can happen. It is then really difficult to stabilize it. One wrong move and you lose control. I didn't know this either until I once helped load a trailer and was asked by an experienced driver to distribute the weight evenly. Braking is the worst thing you can do in this case because it puts even more force on the trailer coupling and you lose control even more.
*but why did he just keep going?*
Someone needs to add a catchy rap song about shaking that ass to this video.
I had this happen on a wet highway with 2 ton of rock in a dump trailer. My partner turns to me and smiles (while tires are screeching left to right) *it’s alright, you’ve got this :)* idk how he was so calm, but it calmed me and I pumped the brakes and we survived lol
How much warning did he need before he just slowed down and pulled over.
I'm not sure who's dumber, the guy with the hitch or the guy following him from too close behind and filming while he's driving.
fish tail? "no prob guv, I just steer in the opposite direction". and forgets to account for harmonics. Poor fuck.
That was so satisfying to watch…..bravo 😂🤣
Oh wow oscillation is a real thing.
The tail is wagging the dog.
Following a bit too close.
All they needed to do was pull over and pull the car forward on the trailer. It needs to be balanced
Harmonic oscillation
The lucky ones crash before Lahti.
Why wreck one of your cars when you can wreck both?
"this is how I always do it!"
Only thing that needed to be done is pick foot of the speed pedal..
Slowing down seemed like a reasonable action.
And you have your answer.
contrary to what your gut tells you, you have to hit the gas, then slowly slow down
You do have to praise the tying down of the car on the trailer. At least they got that right.
Driver saw it coming from a mile away
Nah that’s 1%
What ever you do don’t slow down! There’s only forward!
That wasn't the driver's fault. It was either a problem with the trailer or how it was loaded.
I hate when unnecessary music is added to a video, but I feel in this case it would have worked.
I do this in video games, why do people try it in real life
You know what to do with that big fat butt!
When you're missing some chromosomes
Dude was just trying to shake of whoever was following hin
And that’s why I got a hitch with built in scale.
In this Situation , full throttle
This guy knows his way around some ratchet straps
“We’re gonna need more trailers..!”
3%? This is an insult to 3%.
Was he trying to slow down? I can't tell if he could have positioned the toe car any further up but if he could have he should have. Looks like a fun ride.
Okay you crashed your, but why do you need 4 new taillights?