10% TW to 13% TW...did not seem to make any difference

All I can tell you is sometimes it is the road. I -10 pops up from time to time as one of the worst.

I drove onto a section of 4 lane road leaving a town in SD that looked normal but was so bumpy I actually got out to inspect my TT for some sort of problem.

Fortunately it was only about a mile or so before we turned off but we drove it at 35 mph. I was strange to say the least.

Checking your TT on other roads would be the easiest.