NHTSA complaint #11760540

Owner complaint summary

I am reporting a serious intermittent transmission and loss-of-propulsion problem with my 2021 Lincoln Navigator, VIN 5LMJJ3LT6MEL05416. While driving, including at highway speeds, the transmission will unpredictably behave as though it has shifted into Neutral even though the vehicle remains in Drive. When I press the accelerator, the engine responds, but the vehicle temporarily has little or no propulsion. The transmission may then suddenly re-engage and slam or bang forcefully back into gear. This can also happen under very light throttle. I may gently press the accelerator expecting normal acceleration, but instead the vehicle acts as though it is in Neutral before suddenly engaging again. The condition is intermittent and cannot be reliably reproduced on demand, which makes it especially dangerous and unpredictable. I am concerned about losing propulsion while merging, passing, entering traffic, or attempting to accelerate away from another vehicle at highway speeds. The vehicle has previously had transmission adaptive learning/reset procedures performed, but the problem continues. I am aware that Ford/Lincoln has issued technical service information addressing momentary neutral-out, delayed engagement, harsh engagement, and other 10R80 transmission concerns on this generation of Navigator. I am also aware of Ford recall 26S48 / NHTSA recall 26V402 involving certain 2018–2021 Lincoln Navigators. I am not claiming that the recall is definitively the cause of my specific condition, but I believe this intermittent loss of propulsion presents a serious safety concern that should be investigated. I am requesting that NHTSA document and investigate this loss-of-propulsion / neutral-out condition because the vehicle can unexpectedly fail to accelerate and then violently re-engage the transmission while in motion.