Sway Question

drrodder · 05-31-2010, 05:42 PM

Picked up a big TT. 8750 dry wt. towing with proper hitch (15,000 lb), tension bars and old suspension. Level on the trailer was perfect and the truck a bit saggy in the rear. Every time a semi truck with box trailer passed me on the interstate, I got pulled tot he left as the truck approached and then pushed to the right as they passed. I didn’t get the sway control for this rig before towing it home 2000 miles, so it was just straight WDS. The tension might not have been tight enough (read that some where on here in another issue) for the proper adjustment. Looking to add air bags after new springs and would like to eliminate the tension bars if I can. I don’t have the money to buy a 2011 truck with new computer sway control, so that’s out. I have towed my open car hauler all over the states with no tension bars or sway control on my half ton Suburban and with a good weight distribution on the tongue, never had any problems. The RV (see avatar) on the other hand is much larger to wind turbulence (like when the big semi truck pass me). This thing is 12 ft in the air out back. One co-worker pulls his RV with an E350 Van and airbags w/o tension bars on the hitch, but his RV is lower (about 9 ft high) in back and doesn’t have the sway issue I have. I’m also going to add a rear sway bar to the rear axle as this truck doesn’t have one from the factory. I know many of you have the 2000 and newer trucks, but I like my 1986 ¾ ton Suburban for other reasons (other than towing the RV) and would rather stick $$$ into the older model than deal with the new light weight versions on the market today (2009 and newer). I have already upped the gas tank to 40 Gallon and currently on a more powerful engine. I know the diesels are better, but I only plan to tow this thing around about 3 hour drive twice a year and long haul cross country maybe once every three years. So the towing of the truck in minimal use.

Looking for experience on what has worked or not.

MtnGuy · 05-31-2010, 08:09 PM

If a 3/4 Burb is sagging in the back with the trailer hooked up, you probably need add more tension to the bars.

What is the tongue weight and what size WDH bars are you using ??

Air bags will help take the sag off of the back end, but if the WDH bars are adjusted properly, you shouldn't need the air bags. If you were to just use the air bags without a WDH, you are not getting the proper weight back on the front end. I know with my rig, adding a 700 lb. tongue weight to the hitch will add close to 1000 lbs. to the rear axle, and take off almost 300 lbs. off of the front axle. Sounds like you have a heavier tongue weight, so those figures will probably be more. You need to get the proper geometric proportions back into the Burb.

Sounds like a sway control system is a must with your trailer.

MightyMike · 06-01-2010, 01:47 AM

Sway problem-easiest fix is buy a fifth wheel

Kidding aside, I think you will never get away from the "push" from the big trucks. That's a big box pushing a lot of air, and when it gets to your smaller box, the air has to go somewhere. I think you probably don't notice it with your open car trailer because the air has a lot of places to go to, with out pushing the trailer. If i remember corectly (been quite a few years since I towed a regular trailer), the sway controllers don't really help that much with the "push". I used to watch the mirrors constantly and when a truck was going to pass me, I'd just move a little to the right and give him more room. Still have to be ready for the movement, just not as bad. Good luck.

MtnGuy · 06-01-2010, 07:47 AM

Quote:

Originally Posted by MightyMike

Sway problem-easiest fix is buy a fifth wheel

Kidding aside, I think you will never get away from the "push" from the big trucks. That's a big box pushing a lot of air, and when it gets to your smaller box, the air has to go somewhere. I think you probably don't notice it with your open car trailer because the air has a lot of places to go to, with out pushing the trailer. If i remember corectly (been quite a few years since I towed a regular trailer), the sway controllers don't really help that much with the "push". I used to watch the mirrors constantly and when a truck was going to pass me, I'd just move a little to the right and give him more room. Still have to be ready for the movement, just not as bad. Good luck.

I agree that sway control won't totally correct those semis sucking you over into their lane, but it might help if you over correct and get things swaying. I don't know exactly what trailer the OP has, but it with a 8750 lb. dry weight, it has to be a biggie. Sway control should be installed, preferably an integrated system like the Reese Dual Cam of the Equalizer.

Sometimes those semis sneak up on me, and I have to fight a little to keep things straight, but I do the same as MightyMike most of time and just move over a little, and prepare for the turbulence.

In rereading the OPers post, he said the back of the Burb was sagging a little. That is not necessarily a bad think, as the back of the truck is made to carry the weight. But you don't want to take the weight off of the front end......that might actually contribute to some of the sway that the OPer is experiencing. He needs to read the instructions with his WDH, and do the fender measurements to maximize the the operation of his WDH.

drrodder · 06-19-2010, 09:35 PM

Thanks for the tips. There has only been the 1 tow home (about 2000 miles from Phoenix Az to Milwaukee, WI) and I might not have had the WDH set tight enough. IT is a 15,000 lb WDH and I'm looking into adding the REESE cam system to this. It is a big box (12.5 FT high in the rear - my pic doesn't show up here under my name, but is one the site if you click on my "DrRodder" name to see it) and a older truck. I've added a rear axle sway bar to my half tone Suburban and will to this 3/4 ton model (as all the newer trucks come from the factor with one) too. The air bag idea came from a co-work of mine towing a smaller box (not as high) on a E350 Van and he was able to eliminate the WDH bars and to use them to get the truck more level (doing the measurments), but I'll try the tenssion first (when I get the new motor back in the truck). I did watch the mirrors and found the "pull to the right" to lessen the blow help (biggest problem was a lack of engine power to pull it straight and even keep closer to a decent speed), so trucks were a constant issue since those boys could blow by at 70 mph and I had a time holding 50 mph.

**Herk7769** · 06-20-2010, 08:50 AM

Sometimes overlooked is trailer length vs tow vehicle wheel base.

There is a formula somewhere that deals with this. There really is a "maximum safe trailer length" for your wheel base.

I will try to find and post it.

Found this.

http://davidsrvtips.blogspot.com/2009/03/how-long.html

http://www.popupexplorer.com/forum/i...?topic=64507.0

http://www.streetdirectory.com/trave...stability.html

flyrotor · 06-21-2010, 05:43 PM

Air bags might be helpfull, but should not reduce the need for the WDH, the whole idea of the WDH is to put weight back on the front end of your tow vehicle, just pumping up the back end with airbags will not distribute the weight forward, rather act as a fulcrom and lift the front end equally. Keep the WDH regardless of the airbags

**Herk7769** · 06-21-2010, 06:39 PM

Do not increase load carrying ability. Gross Vehicle Weight and Gross Axle Weight are the same before and after installation.

Does not allow you to tow more trailer.

Does not transfer weight from the back axle to the front. Your weight distribution hitch does that.

They do nothing for sway.

So why put them on?
They:

Do keep you from bottoming out and bouncing down the road when your near max load hits a pothole.

They "may" smooth out your ride.

That's about it IMO.
Save your money and buy a high quality weight distribution hitch with sway control.

red.jimbo · 06-21-2010, 11:36 PM

I agree with Lou (not making that mistake again) Put you money into the WD/sway control hitch.

I ended up getting one of the mid-grade "friction" sway controllers and I love it. In a recent trip on I-80 in Wyoming (think wicked crosswinds and fast moving semi-trucks in a big way) I was very pleased with the lack of sway. I could literally feel the hitch fighting back the wind from the trucks, and the whole time the TV and TT tracked right down the middle of the lane while I gently held the steering wheel between two fingers on each hand.

With my setup, the front of my TV was unchanged, 0", and the rear only dropped 1/2". I have the trunnion bars tight enough that I need to raise the trailer about 15 turns on the jack just to get them on the pads. I think that is how it is supposed to be set based on the instructions.

Good luck!

**Herk7769** · 06-22-2010, 07:40 AM

Before we bought the 5th wheel we rented a travel trailer for a year.
This is our hitch setup. It is rated for 12,000 pounds (about as much as possible for our pickup).

Equal-I-Zer Hitch installation pictures from travel photos on webshots

We also were VERY happy with it towing the utra-lite we rented. (about 6,000 pounds). NO SWAY at all.

I bought the hitch not knowing which way we would jump when it can time to buy (5th wheel or TT).

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