As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AIRCRAFT STARTED TO VIBRATE AFTER TAKEOFF. CREW HEARD LOUD BANG WHEN RETRACTING GEAR. RECYCLED GEAR AND SAME NOISE OCCURRED. EMERGENCY DECLARED FLIGHT RETURNED & LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED NOSE GEAR FORWARD DOOR LINK ASSEMBLY. SYSTEM GROUND CHECKED NORMAL.