What was found
AFTER TAKEOFF FROM LAX EN ROUTE TO TOL, AFTER GEAR RETRACTION A LOUD NOISE AND VIBRATION WAS NOTICED IN THE COCKPIT. THE CREW CYCLED THE LANDING GEAR BUT THE NOISE RETURNED. THE AIRCRAFT RETURNED TO LAX FOR AN UNEVENTFUL LANDING. MAINTENANCE INSPECTED THE AIRCRAFT WHICH REVEALED THE LEFT GROUND COOLING FAN ACCESS PANEL NOT PROPERLY SECURED, AND WAS CORRECTED. FURTHER INSPECTION FOUND THE NOSE TIRE SPIN BRAKES WORN, AND WERE REPLACE. NO FURTHER DISCREPANCIES WERE NOTED AND THE AIRCRAFT WAS RETURNED TO SERVICE.