What kind of service do big RVs need, and where is it done?

Any RV dealer who sells Motor Homes should be able to service it. As to rotating the tires, that’s something, on a motor home, that I consider a waste of time and money. All the tire manufacturers agree that tires should be replaced if they are seven years old, by the date code on the sidewall. If they have severe sidewall cracking prior to seven years they should be replaced. Due to the low mileage of most motor homes tire wear just isn’t a problem and tire rotation is just a waste of money. Chassis and engine service though is definitely an item that needs to be kept up with. I have owned and driven Chevy and Freightliner chassis motor homes and both need frequent inspections for loose components and regular lubrication service.