Khawk

My brand new unit has a loud driveline vibration chatter when accelerating from a dead stop as well as a vibration between 65-70 mph. The dealer said it is a Ford issue and they are unable to determine what it is as they say it is a Forrest River issue when the stretched the frame and added additional drivelines. The Forrest River dealer states I have to take it to a driveline shop and deal direct with Forrest River for warranty. The dealer is useless. Any assistance would be appreciated.