As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, AIRFRAME VIBRATION FELT IN CONTROL YOKE AS WELL AS PILOT SEAT. INTENSITY WAS CYCLICAL FROM LIGHT TO MODERATE AT ALL AIRSPEEDS AND ALTITUDES. GREATEST INTENSITY WAS FELT BELOW 6,000 FEET. DIVERTED, AND LANDED UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED A PROPELLER BALANCING. FOUND THE NR 2 PROP IPS TO BE HIGH. R & R NR 2 PROPELLER ASSEMBLY. AIRCRAFT RETURNED TO SERVICE.