I do have a sway control arm. It helps minimize the problem. Still at 65mph it moves more then I like.

I'll work on getting pictures.

 

Hey I didn't see if you mentioned what rating your tires are? If you've got tires that are too wide for that rim and don't have the sidewall integrity they need I'd imagine that is where your problems are coming from.

Hell if they are like BFG's or something just go grab a couple E rated ones for the rear.

 

Define your "equalizer" hitch.

Is it a weight distributing hitch, or an Equalizer Brand hitch?

If it is a weight distributing hitch, you probably need to play with the bars and chain links. Also, maybe a drop stinger to get the trailer as level as possible.....just like a travel trailer.

 

Yes, its a weight distributing hitch. I will try a notch shorter on the chains and see what happens. Is the goal to get the trailer level with the hitch height?

My tires are BFG all-terrains E rated. I have them at 80PSI when towing.

 

I'd suggest a sway control for the hitch setup.
The tire/rim size is most likely the cause.

 

I have 285/75/18 Load range D tires on stock steel wheels. I tow our 30' travel trailer that weighs around 9500Lbs. I have never had any sway or porposing, even when towing short distances with out the friction sway control.

I have noticed though, that it rides more 'solid' on windy mountian roads, if I tighten up the weight dist hitch one link.

 

The goal with any trailer should be to keep it level, or slightly nose down.

If the nose of a trailer is high, it will increase the sway.

Ideally, you should have the ball height set even with the receiver on the trailer when empty.

Load it, then use the weight distro bars to try to get it back to level. Measure your wheel well openings on the truck when empty and when loaded with the trailer on. The distro hitch should make the truck settle evenly, front and rear, not all on the back.

 

Right now the front raises a bit and the rear squats. I 'm going to try one more link on the chains and see if it helps.

 

One more idea........is the ball on your hitch level or slightly tilted back??

When I had my Reese hitch, you could tilt the ball back. That way you get more pull from the weight bars.

If you can, tilt the ball back towards the trailer.

 

Ok here are some pictures of my setup.
I adjusted the hitch one link tighter. It raised the rear of the truck and front of the trailer a good amount. In fact the trailer now is a little high in the front. Thinking of adjusting the car position to get the trailer level and seeing how it works.