NHTSA Complaint #11280522 — 2015 FORD TRANSIT

I HAVE A 2015 FORD TRANSIT 15 PASSENGER VEHICLE THAT WAS PURCHASED IN NOV 2016 WITH 20,000 MILES. APRIL 2019 THE DRIVESHAFT FLEXIBLE COUPLING WAS REPLACED UNDER WARRANTY. IN JULY 2019 WE BEGAN HEARING A NOTICEABLE VIBRATION / SUBWOOFER DRONE / HUM IN THE VEHICLE.THE DRONE DOESN'T HAPPEN AT A SPECIFIC SPEED BUT IS PREVALENT WHEN WE'RE RUNNING 50-70 MPH AND BETWEEN 2000 AND 2500 RPM. THIS DRONE SOUND IS NOT CONSISTENT BUT NOW VIBRATES THE ENTIRE CABIN WHEN IT DOES APPEAR. I CAN STOP THE SOUND BY PULLING FOOT OFF THE GAS PEDAL. HOWEVER IT JUST RE-APPEARS AT A LATER TIME. WE HAVE NOTED THAT IT IS PROGRESSIVELY GETTING MORE FREQUENT AND LOUDER - EVEN VIBRATING THE STEERING WHEEL. I HAD THE AUTONATION UNION CITY, GA DEALERSHIP LOOK AT IT AND THEY EXPLAINED THAT THE TORQUE CONVERTER (TC) IS FAILING AND CAUSING PROBLEMS WITH THE TRANSMISSION -- IT WOULD BE A $3,000 REPAIR. I HAVE SINCE BEEN RESEARCHING THIS AND HAVE FOUND NUMEROUS OTHERS WITH THE SAME VIBRATION AND FOR THE MOST PART - IT APPEARS THE TC WAS THE SOLUTION.. HOWEVER, NOT ALWAYS. PLEASE SEE THIS THREAD - HTTPS://WWW.FORDTRANSITUSAFORUM.COM/THREADS/DRIVESHAFT-DRONE-NOISE-SURVEY.60498/PAGE-7 NEITHER FORD NOR I KNOW THE EXACT SOLUTION UNTIL WE PULL THE TRANSMISSION BUT IT SEEMS THAT THIS IS POINTING TO THE TC?