The contact owns a 2012 Ford Focus. The contact stated that upon starting the vehicle, the engine started to shake violently; occasionally, causing the vehicle to shut off unexpectedly. The contact was able to restart the vehicle. There was no warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed, and the contact was informed that the torque converter was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 81,000.