2 sway bars on a pull behind trailer

Nope...works great. I ran two with my TT.

You can pick one up at Harbor Freight for a few bucks.

You would be better off making some adjustments to try and reduce the effect. More spring rate or more weight at front of trailer.
Also, a better hitch like the Reese Dual Cam with active sway control will both resist sway and push the combination back in line.
There are other brands that offer active sway control but I've not used them.

Howdy. Not certain what you're towing or what you're towing with. If the trailer box is 32 feet plus the hitch, you're about 35 feet in length--pretty fair sized trailer. Now if the tow vehicle is a 1/2 ton, with 1/2 ton tires and suspension, this might be a large part of the problem. One can imagine you're looking like a set of doubles in a wind storm.
We 're running a 30 foot hitch to bumper trailer towed by a 3/4 ton Ram 6.4. Trailer weighs between 6700 and 10,000 (empty, loaded), has 10 ply tires and a Equalizer hitch. Truck weighs about 7500 lbs. and has 10 ply tires. NO SWAY.
Now, if all is good with your rig, check the hitch setup and weight distribution bars for proper adjustment. You might be light on the front tires, tire pressures need adjusting, etc.
This is a good place for questions, keep coming back.

Never had a problem pulling my Jayco 33RLDS that was 35.6 feet long with a Ford Excursion with 1 sway bar. If being passed by 18 wheelers the truck and trailer maybe might move 1/4 inch. but no sway.

Actually 2 sway bars are recommended for a TT over 30'. however. I would do as suggested, and readjust your hitch, and TT balance. I tow a 30' TT with my 150. I have no sway, and the big trucks don't bother me a bit. Strange thing is. I can feel regular vans, and trucks pass. But not the 18 wheelers

I think there are some instructions that specify two for trailers over 24 or 26 ft. Same general idea.

You are right about tractor trailers. Those things didn’t bother me. Small SUV’s and minivans have some funky air pressure waves when they pass ya.

Thanks!


Jeremiah

I should have mentioned I have a 2018 Chevy 2500hd duromax. The sway problem didn't just start with this truck. I've been pulling the trailer since 96 when new. I think the tongue weight is 800 lbs. I always have put max pressure (80 lb) in all 8 tires on the truck and trailer and that does help a lot. The last time I pulled (a couple weeks ago) I did tighten the pressure on the sway bar (tighter) and that did help and took a lot of sway out of it. It don't go back and forth while just driving, but wiggles a little when big rigs pass and some other vehicles. My trailer weighs 8500 empty. I know tongue weight is important. The reason I'm thinking 2 bars would be better is after tightening the one sway bar did help quite a bit and now seems to be more stable, I assume 2 bars would would be even better. It would put even pressure on each side of the tongue and not excessive pressure on just one side. Maybe the whole problem is I just didn't have enough swaybar pressure all along. When it sways or wiggles it makes for a white knuckle drive.

tewitt1949 wrote:
I should have mentioned I have a 2018 Chevy 2500hd duromax. The sway problem didn't just start with this truck.

tewitt1949 wrote:
I think the tongue weight is 800 lbs.

tewitt1949 wrote:
My trailer weighs 8500 empty. I know tongue weight is important.

Yes tongue weight is important and if your numbers above are accurate, then your tongue weight is too light. Your 8500 lb empty TT probably weighs closer to 9500 lbs when ready to take camping. Ideally, your tongue weight should be between 12% - 15% of TT, so 1,140 - 1, 425 lbs for tongue weight.

-Michael

tewitt1949 wrote:
I think the tongue weight is 800 lbs.

My trailer weighs 8500 empty.

Since we now know that you have inadequate tongue weight, that is the problem that needs fixed. A sway control is not a fix.