"While there has been some very good advice here, I think too often we tend to think of weight first. "
That is because most trailer sway problems are from low tongue/pin weights.
Very easy and cheap to check the tongue weight percentage. That includes all weights both axles on truck and trailer axles.
This has to be done as has been described multiple times in this post.
Need weights both with and without WD bars engaged.
If the last picture I saw of truck hitched was with the WD bars engaged you do not have heavy enough bars as the front of the truck appears to be badly unloaded.
We need tongue weight percentage so tongue weight alone does not tell us anything. We also need the total weight of the trailer.
Without knowing the tongue weight percentage you may be wasting money and time looking for other cures that may do nothing to correct the core problem.
