Correcting Trailer Swing

[Crazy Dazz]

We’ve all seen it, some of us have experienced it. Heavy trailer/boat/caravan starts weaving from side to side in increasing swings, pulling the car’s **** with it. In extreme cases this has resulted in horror crashes and death.
So what is the best method for overcoming this?
The pub wisdom was always that you should accelerate to pull the trailer out of its swing. Two things I couldn’t understand about that: When can you stop accelerating, and aren’t you simply making the situation worse by increasing speed and energy.
Others suggest that you should brake, causing the trailer brakes to engage. (Doesn’t help if the trailer’s brakes are RS.)
Opinions?

I got a bit overconfident today, and coming off a slight bend at 90k, the oscillations set in and got steadily worse. I gradually backed off the throttle, whilst still maintaining some positive pressure, concentrated on keeping the car’s front wheels within the lane, and as the car gradually dropped down to about 70k, the trailer settled down.
Kept it to no more than 80k, and had no further problem.
Interestingly, this happened when hauling an AU with an AU, with the car facing backwards to reduce weight on the tow hitch.
2nd trip, hauling yet another AU, turned it around, and whilst the tow car looked badly unbalanced, it actually towed far better. No problems at 95~100k.

[wrongwaynorris]

Largely depends on the axle location of the trailer and wether the load is centralised over the trailer axle and what subsequent towball download is applied to the car .

[redxm]

Originally Posted by Crazy Dazz

with the car facing backwards to reduce weight on the tow hitch.

Theres your problem there, too much weight over the back of the trailer. 99% of the time trailers swinging are caused by improper weight distribution and/or the tow car not set up to tow the load (factory springs/shocks, too small car etc)
You can also prevent it by fitting sway bars to the hitch/drawbar

[RAREV8]

Originally Posted by Crazy Dazz

We’ve all seen it, some of us have experienced it. Heavy trailer/boat/caravan starts weaving from side to side in increasing swings, pulling the car’s **** with it. In extreme cases this has resulted in horror crashes and death.
So what is the best method for overcoming this?
The pub wisdom was always that you should accelerate to pull the trailer out of its swing. Two things I couldn’t understand about that: When can you stop accelerating, and aren’t you simply making the situation worse by increasing speed and energy.
Others suggest that you should brake, causing the trailer brakes to engage. (Doesn’t help if the trailer’s brakes are RS.)
Opinions?

I got a bit overconfident today, and coming off a slight bend at 90k, the oscillations set in and got steadily worse. I gradually backed off the throttle, whilst still maintaining some positive pressure, concentrated on keeping the car’s front wheels within the lane, and as the car gradually dropped down to about 70k, the trailer settled down.
Kept it to no more than 80k, and had no further problem.
Interestingly, this happened when hauling an AU with an AU, with the car facing backwards to reduce weight on the tow hitch.
2nd trip, hauling yet another AU, turned it around, and whilst the tow car looked badly unbalanced, it actually towed far better. No problems at 95~100k.

80ks is what most Ford car manuals will recommend as a top towing speed for (I think ) anything over a ton.

I have seen awful things happen on several occasions with cars facing backwards on a car trailer....I see your point about towing better because of less ball weight but exactly what happened to you (weaving) is why it is best to avoid towing a car like this.
Basically, you don't have enough weight over the ball and the engine weight of the towed car will start to lift pressure off the front of the trailer and the rear of your car and weaving begins!
I tried this quite a few years back with a friend in Scotland and we got about 5 miles before changing our tactics due to the same issue.

[ltd]

Originally Posted by redxm

Theres your problem there, too much weight over the back of the trailer. 99% of the time trailers swinging are caused by improper weight distribution and/or the tow car not set up to tow the load (factory springs/shocks, too small car etc)
You can also prevent it by fitting sway bars to the hitch/drawbar

Agree 100%.
Always make sure that you can easily lift the loaded trailer by the hitch by hand. If you can it means that you have even weight distribution. If it's too heavy to lift, then you'll be putting too much weight on the towball and then you'll end up with a "snake" then most likely a "Crash".

[chevypower]

1. Get a heavier tow vehicle
2. Anti-sway system for the hitch
3. In the heat of the moment, manually use the electric trailer brake controller to apply braking to the trailer only.
4. Get a vehicle that has "trailer sway control."
5. Load the trailer properly so that it is balanced.
6. Make sure the trailer has tandem axles.

[Ben73]

Some 4x4 have trailer sway control from the factory, Have no idea what it is.

When I eventually have to tow heavy stuff, like when I get a boat and/or track car, I will be getting a 4x4 that is setup to tow. And it will have a massive engine so I don't lose too much speed up the hills on the F3

[GTP owner]

I am buying a discovery series 4 with the anti-sway function. It uses the abs on different sides of the car to balance the sway out, much the same as DSC prevents under or oversteer. It is one of the major selling points for me.
As for what to do - DO NOT accelerate. That will make it worse. Do not fight the sway either. You need to gently get off the accelerator, and gently brake. Let the car move around and gently correct the movement to keep things straight.
I have had the sway happen on numerous occasions towing my race cars with falcons at up to (and maybe a bit over) 100km/h. I found that it was very sensitive to where the car was on the trailer. 1 inch too far back would cause severe sway to over 80km/h. 1 inch too far forward would cause the front of the tow car to be too high and the front brakes would lock up due to being unloaded. As for the amount of weight on the towball- if I had less than 150kg the wind resistance on the race car (which sits up in the airflow) would cause it to lighten further and cause sway. If the towball weight was over 200kg, then it would lift the front of the tow car.
Other things to consider are tyre pressures. I run mine at 45psi at the rear of the tow car and the trailer. Also make sure the car is very tightly pulled doen on the trailer

[vanman_75]

Had you put the car on forwards you would have no problems at all ,major problem . Caravans you see with all the storage under the rear bed,and people not knowing better .balance is the key with preferred weight forward and if that causes the wheels to lift you need to either put levelerson your tow bar or use a bigger vehicle .

[mik]

back when i was a teenager i was a passenger ina 68 f100 with spongey singles on the back with a load of bricks, also on the f100 with a rather large tandem in tow with a very kaput xk falcon on the back(poorly restrained, balanced, and overloaded) , i had a very short but hair raising ride.
we may have gone half a k .............. the old girl got the colly wobbles up very quickly and jack knifed, the xk under took us and ended up in someones front yard, the f100 before departing company with the trailer went up on 2 wheels, very close to going over, spinning around faceing the opposite direction , the trailer neatly parked itself in the gutter on the other side of the road, i remember to this day that i commented on how spongey the tyres were prior to our little jaunt, i believe this one thing had it been addressed may have saved our bacon, but all the other points made in this thread are very good ones.

[Peuty]

Originally Posted by Ben73

Some 4x4 have trailer sway control from the factory, Have no idea what it is.

It's a function of the EBD/ESC system where the car will sense trailer oscillation and apply brake pressure to individual wheels to bring the sway under control.

[GreenMachine]

I've always found smoothly and gradually accelerating until the swing corrects and then braking down to a safer speed does the trick.

Have had some horribly hair raising moments with dodgy service station car trailers, including one where the AU wagon tow car, the trailer and the ZH Fairlane on it were taking up both lanes of the Bruce Highway for about 200 metres before I got it straight. My mate who was with me has never fully recovered from that.

[Neeek]

And I won't ever sit in a car towing more than its own weight ever again. Unless the tow car is a truck. At least the ZH was engine-less!

[burnz]

use load equallizing hitch!!

most caravans have them as standard..

[GreenMachine]

Originally Posted by Neeek

At least the ZH was engine-less!

Yes, that would've saved the SES getting a second crane to get us out of the ditch.

Regarding braking, obviously it depends on the state of the trailer and car brakes, but I've found that often when the trailer is weaving around, applying the brakes will often make it have one good, big final swing, which is unhelpful.

As people have said, loading and weight distribution is critical, but there are also some horribly unsafe car trailers out there, particularly ones from service stations - brakes that only grab on one side, mismatched tyres, poor design that doesn;t allow you to get the weight distribution right...

[Ben73]

I remember driving on the F3 at 1am 2 years ago. A 90s model Toyota Camary towing a boat passed us at easy 110-115km/h just as we passed one off those signs that says 'High wind area' and has a picture of a car towing a caravan.

Needless to say midway across the bridge the car got major trailer sway that it took up all 3 lanes of the road, missed the guard rail by an inch and the guy finally regained control about 1 meter from the other guard rail at about 40km/h. It amazed me that he did not completely lose it.

Then he pulled to the side of the road, probably to change his pants.

[Landau Stable]

I have towed with my car trailer thousands and thousands of kms over the last 10 years. The majority has been on the hume highway. The trailer has been the same, but the tow vehicles have changed as i get bored and move on.
There's a few things to think about when towing a car on a tandem trailer. Getting a good load distribution is paramount. As a rule of thumb, if you have a hard suspension, you want it to drop 1-2 inches. If you have a soft suspension, you want it to drop 2-3. If you have no motor or box, then it's best to load backwards, unless your trailer is long enough to push the car so far forward, that you still get that drop in your suspension. Don't let the suspension drop too far than mentioned, or you risk losing your front brakes in a hard stop, as they will lock up. The rear suspension will act like a pendulum and lift your front wheels if it has too much weight. Conversely, if you don't have that drop in suspension as mentioned, you will get the death wobbles in no time, and are asking to be killed.
Another paramount item. Drive according to your limits! If you start to get the death wobbles at 85km, then drop down to 80km or less for the rest of your trip. Don't try and be a hero and keep pushing the limit for an extra 5km. A properly loaded trailer will still sit on 110km if the tow vehicle is heavy enough, but once your load is heavier than your tow car, you will be limited to about 80-90.
I highly recommend electic override brakes for the trailer. A gentle touch on the pedal will send no braking effort to your car, but will jolt the trailer straight, and then allow you to push your pedal down with some force to slow you down. The electric brakes also have a manual switch to get the trailer brakes on too, if you aren't confident in judging what a gentle touch is on your pedal.
What to do once you get the wobbles? DO NOT speed up. Speed is what induces the wobbles in the first place. back off, and let the car coast. Do not fight the wobbles, by trying to correct it with the steering wheel. You will end up jerking the car and making it worse. Instead, go with the flow, and GENTLY try to bring it back. It has to be a gentle and fluid motion on the wheel. If you are on the straight, backing off and coasting will slow you quickly enough to recover in a few seconds.
Most of the time, you get the wobbles downhill, and that is when it is most dangerous. Apply the brakes as i mentioned before. if you have no trailer brakes, you will need to start applying car brakes anyway. again, smooth is the key. Apply them reasonably hard, yet fluidly and try to maintain a steady speed. once you get that under control, ease up the steering as mentioned earlier, so that you don't jerk it around, and keep applying the brakes to slow down and get below the speed that induced the wobbles in the first place. Any hard movements on the brakes or steering will send you undone.
always look ahead when towing on the highway. if you see a crest, slow down at the top, so that you aren't on the brakes the whole way down the hill. No point in overheating them half way down, and discovering that you suddenly need them to work at their best. if you see a long hill approaching, then you can give it a little more speed on the flat, as the hill will help prevent the wobbles by having the trailer pull back on the car, hence allowing a bit more speed as you go up. that way you aren't stuck doing a crawling pace half way up.

The worrying part about all of this, is that you need to get a licence if you wish to drive a MR or HR truck etc, and need to prove that you know how to load your vehicle etc. Yet anyone with a car licence can hook up a car trailer and off they go. no training or education whatsoever. Stay safe folks.

[LUXO_8]

Originally Posted by Landau Stable

I have towed with my car trailer thousands and thousands of kms over the last 10 years. The majority has been on the hume highway. The trailer has been the same, but the tow vehicles have changed as i get bored and move on.
There's a few things to think about when towing a car on a tandem trailer. Getting a good load distribution is paramount. As a rule of thumb, if you have a hard suspension, you want it to drop 1-2 inches. If you have a soft suspension, you want it to drop 2-3. If you have no motor or box, then it's best to load backwards, unless your trailer is long enough to push the car so far forward, that you still get that drop in your suspension. Don't let the suspension drop too far than mentioned, or you risk losing your front brakes in a hard stop, as they will lock up. The rear suspension will act like a pendulum and lift your front wheels if it has too much weight. Conversely, if you don't have that drop in suspension as mentioned, you will get the death wobbles in no time, and are asking to be killed.
Another paramount item. Drive according to your limits! If you start to get the death wobbles at 85km, then drop down to 80km or less for the rest of your trip. Don't try and be a hero and keep pushing the limit for an extra 5km. A properly loaded trailer will still sit on 110km if the tow vehicle is heavy enough, but once your load is heavier than your tow car, you will be limited to about 80-90.
I highly recommend electic override brakes for the trailer. A gentle touch on the pedal will send no braking effort to your car, but will jolt the trailer straight, and then allow you to push your pedal down with some force to slow you down. The electric brakes also have a manual switch to get the trailer brakes on too, if you aren't confident in judging what a gentle touch is on your pedal.
What to do once you get the wobbles? DO NOT speed up. Speed is what induces the wobbles in the first place. back off, and let the car coast. Do not fight the wobbles, by trying to correct it with the steering wheel. You will end up jerking the car and making it worse. Instead, go with the flow, and GENTLY try to bring it back. It has to be a gentle and fluid motion on the wheel. If you are on the straight, backing off and coasting will slow you quickly enough to recover in a few seconds.
Most of the time, you get the wobbles downhill, and that is when it is most dangerous. Apply the brakes as i mentioned before. if you have no trailer brakes, you will need to start applying car brakes anyway. again, smooth is the key. Apply them reasonably hard, yet fluidly and try to maintain a steady speed. once you get that under control, ease up the steering as mentioned earlier, so that you don't jerk it around, and keep applying the brakes to slow down and get below the speed that induced the wobbles in the first place. Any hard movements on the brakes or steering will send you undone.
always look ahead when towing on the highway. if you see a crest, slow down at the top, so that you aren't on the brakes the whole way down the hill. No point in overheating them half way down, and discovering that you suddenly need them to work at their best. if you see a long hill approaching, then you can give it a little more speed on the flat, as the hill will help prevent the wobbles by having the trailer pull back on the car, hence allowing a bit more speed as you go up. that way you aren't stuck doing a crawling pace half way up.

The worrying part about all of this, is that you need to get a licence if you wish to drive a MR or HR truck etc, and need to prove that you know how to load your vehicle etc. Yet anyone with a car licence can hook up a car trailer and off they go. no training or education whatsoever. Stay safe folks.

this is brilliant advice (having towed cars/caravans....oh...once or twice lol), please take this on board people!
i also think people should have to hold a licence for towing... some of the crap i see is so epic dangerous

[LANKY 1]

I had this once, i was driving a small tractor towing a bagging machine (about twice as wide as tractor. while going over a bridge i had to do a quick steer cos a car was coming and this caused the back wheels to start sliding! backed off the throttle and put foot on clutch and counter steered, was damn lucky not to go over the edge into the river 20m below

[zeuss000]

Well this thread has just helped me make a decision as to weather to drive from Gold Coast to Victoria to pick up an XC i have just brought, Not a chance in hell after reading all these horror stories Think i'll just have to cop the $770 and have the transport get it here safely, even if i do have to wait 2 more weeks . Better safe than sorry, plus the gearbox on the AU isn't really up to the job anyway, cheers for all the info guys..
Ed

[Legit290]

i have had it happen a couple of times, first stupidly accelerating with a car on a car trailer and the second and most scary moment of my life was when a truck overtook me when i was towing a big boat doing about 90km and sucked the trailer all over the road. One of the left trailer wheels parted company and sped into the bush after keeping up with me for a while.

in both cases i tried to back off and/or brake. with the car on the trailer the swinging got so bad it felt like the back wheels of my old XT were coming off the ground. I accelerated pulling the trailer straight and the swing stopped. I then eased off the separator and got it under control

with the truck suck i tried to accelerate, i tried to back off, i tried to brake i thought we were dead, my br in law crapped himself and nothing seemed to work until the speed washed off and i was able to ease off onto the shoulder, stop, then look for the wheel still with hub attached in the bush.
i am a fan of accelerating out of it, it has saved me the first time. second was a fluke
load things properly, don't go too fast, don't tow things that are beyond your car or your capabilities.

[wrongwaynorris]

Originally Posted by zeuss000

Well this thread has just helped me make a decision as to weather to drive from Gold Coast to Victoria to pick up an XC i have just brought, Not a chance in hell after reading all these horror stories Think i'll just have to cop the $770 and have the transport get it here safely, even if i do have to wait 2 more weeks . Better safe than sorry, plus the gearbox on the AU isn't really up to the job anyway, cheers for all the info guys..
Ed

I know you mentioned your tranny may not be up to it but if you load the car on the trailer properly there will never be a problem , spent ten years towing my race car all over the place and ever since have been towing trailers with sweepers , scrubbers , generators and currently lighting towers without a single incident .

[Peter B - CV8]

Never load a front engined car onto a trailer backwards, it should always face forwards - so the engine & majority of car weight is close to the towball.

[zeuss000]

Originally Posted by wrongwaynorris

I know you mentioned your tranny may not be up to it but if you load the car on the trailer properly there will never be a problem , spent ten years towing my race car all over the place and ever since have been towing trailers with sweepers , scrubbers , generators and currently lighting towers without a single incident .

Yes it it wasn't for the box on the AU then i would probably do the trip, i towed a boat from Perth to Brisbane behind a XBGS Panel van once, ( 20 years ago) that was a long haul tho i must say i enjoyed it immensly, not quite as much fun as driving the XA Superbird from Brissy to Perth but still a nice drive

[redxm]

Originally Posted by LUXO_8

i also think people should have to hold a licence for towing... some of the crap i see is so epic dangerous

+1

Should be two classes of towing licence, box/boat trailer single axle & then duel axle. Some people have no idea even towing the rusty box trailer to the tip.

[BigAL_250]

Yeah, this is what happens when you've got too much weight over the back of the trailer.

And yes, that's me down there.

[svo supporter]

I have found actually knowing the trailer is the best thing when it comes to loading. I actually find it better to load mine, with the car facing backwards. I find when the car is on forwards, I can't travel more than 80 K on the open road. With it on backwards, no worries doing the 110K.

As for swaying. LANDAU STABLE hit the nail on the head, when it comes to controlling it.

[20focus05]

Also use lower gears to help going down hill
You can even do this with autos it will not hurt them.

[GasoLane]

Originally Posted by Crazy Dazz

Interestingly, this happened when hauling an AU with an AU, with the car facing backwards to reduce weight on the tow hitch.

Bzzt! as others have said, big mistake. Too much weight on the rear of the trailer which is lifting the rear of the car, causing the swing.

Originally Posted by Crazy Dazz

2nd trip, hauling yet another AU, turned it around, and whilst the tow car looked badly unbalanced, it actually towed far better. No problems at 95~100k.

Good to see you're a quick learner [/QUOTE]

Originally Posted by ltd

Always make sure that you can easily lift the loaded trailer by the hitch by hand. If you can it means that you have even weight distribution.

This is NOT what you want. The front half, in this case the four wheels of the car, should always have more weight on them than the trailer.

[Franco Cozzo]

When I was doing the hydraulic brakes book at TAFE it mentioned that just activating the trailer brakes will stop it from swaying.