As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRFRAME VIBRATION ABOVE 260 KIA APPEARS TO BE COMING FROM RUDDER. RUDDER PEDALS DANCING BACK AND FORTH. CAN BE FELT IN YOKE AS WELL. VIBRATION GOES AWAY BELOW 250 KIAS. CHECKED WITH YAW DAMP OFF AND VIBRATION STILL PRESENT. FOUND ELEVATOR AND RUDDER TRIM TAB HORN BEARINGS WORN EXCESSIVELY. BEARINGS REPLACED.