As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNKNOWN VIBRATION. NOSE LANDING GEAR LT AFT DOOR ROTATING ROD SPANNER NUT LOCK WASHER BROKEN, AND BENT LOCKING TABS WHEN TORQUING NUT. REPLACED LOCKING TAB PER MM AND REINSTALLED NLG AFT DOOR. DOOR ADJUSTMENT AND GEAR OPERATION NORMAL.