POWER TRAIN · VEHICLE SPEED CONTROL · ENGINE
I am reporting ongoing safety-related powertrain and drivability concerns involving my 2021 Ford Explorer ST in Fresno, California. The vehicle has experienced recurring transmission and driveline problems, including harsh or delayed shifting, hesitation, abrupt gear engagement, jerking/surging, and inconsistent acceleration. These symptoms are similar to transmission concerns documented by Ford for 2021 Explorers equipped with the 10R60 automatic transmission, including harsh/delayed engagement or shifting and potential issues involving transmission controls, solenoid strategy, and main-control valves. The vehicle has also required CV axle/half-shaft repairs, raising additional concerns regarding driveline reliability. I am also concerned about the known rear differential/rear axle mounting-bolt defect affecting 2021 Explorers. Ford has documented that the rear axle mounting bolt may fracture, allowing the axle housing to move. This can result in severe vibration/noise and possible driveshaft or half-shaft disconnection, potentially causing loss of propulsion. The defect may also contribute to a vehicle rollaway hazard. These combined transmission, CV axle, and rear differential concerns create a significant safety risk. Delayed acceleration or engagement can prevent the vehicle from responding as expected when entering intersections, making left turns, merging onto highways, changing lanes, or avoiding hazards. Abrupt engagement after hesitation can cause unexpected vehicle movement. Failure of a CV axle, half-shaft, or rear axle/differential mounting component could cause sudden loss of propulsion or vehicle control. I am requesting that NHTSA investigate whether these recurring transmission and driveline problems represent a broader safety defect involving the 10R60 transmission, CV axles/half-shafts, rear differential mounting system, or related powertrain components.