getting some waggle

Max PSI in tires, both TT and truck. Measure the front of the truck hitched and unhitched. Are you returning it to near original height? Just looking at it doesn't count. You didn't have sway before so it's either the truck or the WD setup.

Tires are aired up COLD. You can't drive for 30 mins then check them.

I have the same hitch...try adjusting the chain to put more weight on the back of the truck and air your tires up to max pressure. My Tundra had to have 3 links hanging...my RAM rides much better with 2 links or even 1 link hanging...

Yep, it sounds like tires to me. I don't know why you are reluctant to fill them to the max sidewall pressure though. I run my trailer tires there all the time (65)I run my truck rear tires at 80lbs (max) and fronts at 75. Also that pressure is when the tires are cold. Don't worry about the increase after towing for a while. They are designed to withstand that increase.
Barney

ken56 wrote:
I am at 2 links on the bars now, do I need another one?

Hitch...I think is properly adjusted for this truck.

Those seem like contradictions.

Check the front axle weight or estimate my fender height of no trailer attached, with tongue on ball, and with WD bars attached.

I would also add some air, 45-50psi cold to all 4 tires.

The hitch is a Pro seires 10k/1k with a friction sway bar. Hitch is fine and I think is properly adjusted for this truck. tow config is level when hooked up. I am not getting sway, just some waggle in the rear end of the truck at times, not continously. Tires are at 35psi now, side wall says max is 51psi. I notice I gain about 5-7 psi when towing and heated up. They are nitrogen filled. I do not know exact tongue weight but am sure weight is more forward then rearward. I do not get any bouncing in the truck either, suspension is good to carry the weight, just getting slight side to side waggle. I am suspecting its the tires but am cautious about filling them to max psi. The old rig and truck pulled flawlesly but it had Michilins on it.

If the only thing that has changed is the truck then that has to be the reason. It should have nothing to do with the trailer tongue weight since it towed well before.

If the height of the hitch receiver is the same as the previous truck, then the problem points to the tires. You should not have to change the number of links or anything. If it is different, then I would check the hitch setup, air up the tires to max sidewall pressure and try towing it again.
Barney

You need to set up the W/D hitch for the new truck and check the proper air pressure in your tires.

Make sure you have enough tongue weight. Biggest cause of sway issues. Also check to see if trailer is level.

First things first. Either get new tires or get the one you have aired up to max pressure. I am a proponent of LT tires on all trucks. You do not need to go to an E rated tire as you will never use them to their potential. Get some D rated,your dealer may have to order them in but they are readily available.
Once you have the tires squared away go from there. Your trucks hitch is probably an inch or two higher than what your suv had so adjustment will be needed to neutralize that.
Did you tow the trailer loaded as normal? In my case if I have empty tanks I need three links, with full I go to four.
Let us know what you came up with!

One thing to consider -- is the weight in front of the axles greater than the weight behind the axles? Too much weight behind the axles will cause sway. Also a factor in tongue weight issue.