As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL INFLIGHT T1245/28MAR - AFTER TAKEOFF AND GEAR HANDLE RAISED AIRCRAFT BEGAN VIBRATING TOWARD NOSE AND BELOW OUR FEET. CYCLED GEAR DOWN. VIBRATION REDUCED BUT CONTINUED. RETURNED TO STL AND LANDED WITHOUT INCIDENT. REPLACED RIGHT NOSE GEAR DOOR ACTUATOR. SYSTEM GROUND CHECKED NORMAL OPERATION.