Couple of questions on trailer sway

[CChase]

First question I have is I know what initiates sway (passing trailer, evasive manuever, etc) but what causes it to compound? Is it the wind that hits the side of the trailer and "springs" it back the other way, back and forth, or is there something else at play.



Second question is, I was reading in the Jordan manual that you should not use the manual brake override to correct trailer sway. Having been around trucking most of my life, I know that if a trucks trailers starts to sway, they apply the trailer brakes to correct it. Is there something that makes electric brakes different, or why do they say that you shouldn't do it?



Thanks

Craig

 

[CHinton]

I'm not confident enough of my knowledge on the first question to answer.



On the second one, I had found a good site that discussed the physics of sway. It was focusing on big rigs, but applied in our case too. One of the big issues in using the trailer brakes is that you do not want the trailer brakes to lock-up. Depending upon road conditions (slick from rain, snow, etc) if you have your trailer brakes set-up for dry pavement and use them, the trailer brakes are very likely to lock-up and the trailer would continue to slide out of control. I believe the brake controller people don't want to go into all the details and just say don't use them in that circumstance. Wish I could find that site again...



Sway and stopping/controlling/avoiding are discussed at length and often on the rv.net forums as well.



My 2cents worth...



Chad

 

[rblomquist]

First question I have is I know what initiates sway (passing trailer, evasive manuever, etc) but what causes it to compound? Is it the wind that hits the side of the trailer and "springs" it back the other way, back and forth, or is there something else at play.



Second question is, I was reading in the Jordan manual that you should not use the manual brake override to correct trailer sway. Having been around trucking most of my life, I know that if a trucks trailers starts to sway, they apply the trailer brakes to correct it. Is there something that makes electric brakes different, or why do they say that you shouldn't do it?



Thanks

Craig

First ?: To me, the biggest single factor in reducing trailer sway is load configuration. I had more sway than I cared for at first but when I adjusted the way I load the thing it greatly reduced the back-and-forth.



Second ?: The way I was trained (dad was a trucker) was to apply manual brakes to get it back under control. I've never had a problem with that concept using electric brakes. It's either use them or ride the sway out and hope you keep it top-side up.

 

[jcarew]

Trailer Sway

I have found that the main cause of trailer sway has been not enough hitch weight. The hitch weight should be at least 10% of the trailer weight an up to about 13%. it pays to weigh your vehicles an know their weights.

 

[jelag]

I agree with jcarew..... I use some comerical trailers that were built for a special purpose... we designed them for 60% of the weight in front of the axles and 40% behind the axles... If you don't have enough tongue weight you will have tow problems for sure... .



Remember that on Class 8 trucks and trailers the axles are at the end of the trailer and the load is between 2 heavy sets of axles... that's why on those trucks the driver can hand set the trailer brakes and pull the thing back into line... . In some cases where the driver owns the tractor and the company he works for owns the trailer, he'll use the hand (trailer brakes) lever to stop the whole load when its safe... thus saving the tractor brakes..... (his tractor)...



Jim

 

[CChase]

Thanks. I have never towed a long TT and luckily have never gotten into a swaying trailer situation I was just curious because I tow the excavator in my sig, and was curious how suceptible to sway it is. I have it figured out wher to position it for 10-15% tongue weight, I was just asking for future when I do devide to get a TT.



Thanks again,

Craig

 

[Prairie Dog]

Often It's the short trailers that sway the most! I went from a 22' to a 26' and left behind all my sway problems. Also the instructions that came with my sway control said you may need one on each side if you tow a very short trailer.

 

[RBoode]

Use a hensley hitch,,, It works... there is no sway

 

[ndurbin]

I'll second the short trailers swaying more. Single axle trailers seem to be worse about it too. We had problems one time with a small 10-15' enclosed trailer, it would bounce and sway all over the place. We found by moving the load inside towards the front and using a drop hitch dropped the swaying ALOT.



I've noticed with my gooseneck stock trailer (31' overall) if I get the load (cows usually) to far forward it doesn't handle nearly as well. I've also played around with the hitch height since it has an adjustable hitch. And the lower I can have the hitch height the better it rides.



Nathan