As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT PILOT REPORTED ACFT BEGAN TO SHAKE VIOLENTLY. RUDDER PEDALS SHOOK. NO ENGINE ANOMALIES NOTED NO OPEN DOOR INDICATIONS. FLIGHT WAS DISCONTINUED AND ACFT RETURN TO DEPARTURE AIRPORT. UPON INSPECTION THE CLEVIS FORK THAT ATTACHES THE RUDDER GEAR TAB ROD TO THE GEAR TAB MECHANISM WAS FOUND TO BE SHEARED. THE MECHANISM WAS FOUND TO OPERATE SMOOTHLY AND THE TAB WAS FOUND TO MOVE FREELY ON THE HINGE.