In your other thread you said, “At certain speeds, and only when the truck (in signature) is heavy with either people, cargo, or the TT (tongue weight per Jayco is 470 dry), the truck has an 'almost-too-low-and-too-deep-to hear' rumble that lasts until the truck gets either above or below the 'problem' speed....it happens at around 10mph and again at around 35 mph..”
So it seems to me the dealer really isn’t at fault for testing with a load in the bed since that was one of the things you said caused the vibration.
Deep rumbling when truck loaded (with cargo or TT)
