I guess you are referring to Tiffin in Alabama. They do build their own chassis for some models but it was not cobbled together. They had the design developed by a company with engineers that had extensive experience designing diesel motorhomes. Issues with the chassis is not typically the reason owners travel back to the factory service center.
Spartan, Freightliner, and Ford provide most of the Class A chassis for the industry and all 3 are very good at what they do. Again, chassis issues are not that common but the rest of the motorhome build can vary from great to horrid...
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