The contact owns a 2018 Ford F-150. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. Additionally, the transmission shifted hard, and the power train warning light illuminated. The vehicle was taken to the dealer where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The contact was informed that parts for the repair were on back-order. The manufacturer was made aware of the failure and a case was filed. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 80,000.