There are 4 owner-reported powertrain & transmission complaints for the 2021 Lincoln Navigatorin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
While driving, the vehicle repeatedly hesitated during gear changes, lost power, and then abruptly jerked back into gear. This occurred intermittently for over a month without any warning messages, creating unpredictable and unsafe driving conditions. As the issue worsened, the vehicle began losing power more frequently. The most serious event occurred at highway speed, where the vehicle suddenly lost propulsion in the middle of active traffic, nearly causing a stall. This created an immediate safety hazard for myself and surrounding drivers. After several seconds, the vehicle violently re-engaged into gear and surged forward. Only at this point did the vehicle display a warning: “Powertrain Malfunction / Reduced Power.” I scanned the vehicle and retrieved DTC P0734 – Gear 4 Incorrect Ratio, a code associated with internal transmission faults. A dealership inspected the vehicle and reported that the CDF drum had failed. They stated they could not guarantee that replacing the drum would resolve all issues and provided two estimates: $5,600 for a partial internal repair/$8,700 for full transmission replacement. The 10R80 transmission has a documented history of failures, including harsh shifting, slipping, unexpected gear disengagement, and internal component defects. These issues are addressed in multiple Ford Technical Service Bulletins involving P0734, harsh/failed shifts, and failures related to the CDF clutch cylinder/drum. Many vehicles of the same make and model are covered under related recalls or service actions for similar problems; however, my VIN is not included, and Lincoln declined to honor the existing recall. This defect presents a serious safety risk due to: Sudden loss of power while driving, including at highway speeds, Unpredictable re-engagement and violent surging, Loss of propulsion without warning, leading to near-stall conditions. This powertrain malfunction is a known, unsafe, repeat issue among these vehicles equipped w/this transmission.
Navigator transmission goes into neutral when accelerating at speeds of 50+. Trans completely overhauled. Still does it. Almost had 2 accidents when changing lanes on the freeway, trying to accelerate and instead slowing down with cars behind fast approaching . When trying to pass on a 2-lane hwy, this would be deadly.
Car stalls often. Was not able to go through intersection. Held up traffic. Another incident was I was almost rear ended when car lost power. This is dangerous and not just an inconvenience.
Within one week of delivery of this new vehicle, the transmission began slipping out of gear and the car loses power for 30-40 seconds in the middle of driving. Shift System Fault, Transmission failure, and PowerTrain Malfunction are the errors coming up on the screen- even after the vehicle was in Service for 2 weeks and they replaced the transmission valve system. Very dangerous to completely lose power on the highway.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026