The contact owns a 2018 Ford Explorer. The contact stated that while his wife was driving at an undisclosed speed, the vehicle began to vibrate excessively. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA hotline for assistance. The failure mileage was unknown.