DrewE wrote:
It would not void a warranty per federal law. You can legally only be denied coverage based on an aftermarket part or addition if the failure was caused by the aftermarket part. Since the chassis is designed to be able to tow more than the current hitch allows, there's pretty much nothing that a properly installed, higher-rated hitch would do that falls into that category.
Do note the "properly installed" bit, which might not be perfectly straightforward on a motorhome with the typical frame extensions.
This is exactly correct. The Magnuson-Moss Warranty Act prohibits voiding a warranty because of aftermarket equipment if that equipment had no effect on the failed part. An obvious example, a higher rated hitch installed would not void the warranty on the RV refrigerator but could void a warranty on the frame rails to which the hitch is affixed.