As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF AND CLIMBOUT, GEAR RETRACTION HAD RUMBLING FROM NOSE GEAR AREA. RECYCLED GEAR, NOISE STOPPED ON DOWN CYCLE BUT RETURNED ON THE RETRACTION. AIR TURNBACK TO MHR. FOUND LOOSE NR 2 CTC DUCT. ADJUSTED AND SECURED DUCT. NO OTHER DEFECTS NOTED.