Have you weighed it loaded and adjusted PSI according to the tire manufacturers chart? The F53 is notorious for getting a lot of road feedback especially on a lighter coach with a lot of sprung weight. The PSI recommendation on my rig was actually a lot higher than the tire manufacturer recommended for my coach when it was weighed for travel. I was able to drop about 5 psi per tire which doesn't sound like much but it made a nice difference. Rough roads are still a problem on any F53. Some have replaced the shocks and had good luck.