As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF OUT OF KIAH, THE CREW FELT A SEVERE VIBRATION AND LOUD NOISE COMING FROM THE NOSE GEAR AREA, WITH THE GEAR UP OR DOWN. THE CREW RETURNED TO KIAH AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE LANDING GEAR AND FOUND THE LEFT FORWARD NOSE GEAR DOOR SEAL AFT HALF MISSING. MAINTENANCE REMOVED REMAINING GEAR DOOR SEAL. THE AIRCRAFT WAS RETURNED TO SERVICE.