The contact owns a 2023 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that while driving at speeds of 70-75 MPH or faster, the vehicle failed to accelerate or downshift without warning. The RPM increased; however, the vehicle failed to accelerate. The vehicle hesitated and jerked while changing gear. The dealer was contacted and diagnosed that there was metal in the oil which could cause engine failure. The dealer had performed several firmware updates; however, the failure persisted. The manufacturer was made aware of the failure and opened a case. The failure mileage was 41,000. VIN tool confirms parts not available.