POWER TRAINCategory: Power Train -> Automatic Transmission Subject: 2020 Lincoln Navigator β Repeated Missed Warranty Repairs β Transmission Neutral-Out & Violent Downshift at Highway Speed Description: On [XXX], while traveling at approximately 70 mph on [XXX], my 2020 Lincoln Navigator suddenly downshifted, free-wheeled into neutral, then violently re-engaged into a lower gear, chirping the rear tires and nearly causing a collision. The vehicle displayed a "Shift System Fault" warning. This defect matches TSB 23-2120 (momentary neutral-out) and TSB 24-2101 (harsh/delayed engagement) for the Ford/Lincoln 10R80 transmission used in the Navigator. TSB 23-2123 (harsh/delayed engagement/shift) also applies to my model year and transmission. I purchased this vehicle in December 2023 from Performance Lexus RiverCenter (Covington, KY) with the original Lincoln 6-year/70,000-mile powertrain warranty still in effect. According to Carfax, the vehicle was owned by Airport Ford, a Ford/Lincoln dealer, for six months prior. No transmission-related repairs were performed during that period despite applicable TSBs. In March 2024, I reported abnormal shifting to Lincoln of Cincinnati. The concern was dismissed without inspection or repair, even though the TSBs applied to my VIN at that time. The [XXX] incident is the direct result of two separate failures by Lincoln/Ford dealerships to act on a known defect while the vehicle was under warranty. This is a serious safety hazard that can cause sudden loss of power and traction at highway speeds. Vehicle Details: - Year: 2020 - Make: Lincoln - Model: Navigator - Transmission: 10-speed automatic (10R80) - Mileage at Incident: 48000 - VIN: [XXX] - Date of Incident: [XXX] - Dealers Involved: Airport Ford (prior owner), Lincoln of Cincinnati (service visit March 2024) The dealer is working on the car currently will send any repair items when they are in hand INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)