JMGNole wrote:
The tires are the prescribed tires, properly inflated, and brand new that morning.
The trailer was empty, except for the furnishings and water.
The extreme sway event was caused by us being undercut in traffic.
Acceleration and going up hills is a struggle, even with the tow package engaged.
You are going to need to check that the tires are inflated to their MAXIMUM if you are running that kind of weight. My Sierra tires run at 36 psi all year but I increase that to 44 psi when towing the trailer. That 8 pounds makes a massive difference.
It also appears like your tongue weight might be too light. Sometimes a WDH (weight distributing hitch) has clamp style hardware that can slip. I had a terrible sway suddenly one time, pulled into a service center, and found that one side of my hardware had slid forward on the tongue. The WDH was therefore not working correctly one one side, it caused all sorts of sway. I adjusted the position and tightened it down, all was good after that.
