As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE NR 1 OIL QUANTITY GAUGE ROLLED DOWN TO ZERO EN ROUTE. TEN MIN LATER LOST PRESSURE AND LIGHT ILLUMINATED. PERFORMED PRECAUTIONARY ENGINE SHUTDOWN. FOUND LOOSE FITTING ON BOTTOM OF GEARBOX. RETORQUED PER JT8D MANUAL, INSPECTED MAIN OIL FILTER AND NO DEFECTS NOTED. RAN ENGINE AND PERFORMED LEAK CHECK, NO LEAKS NOTED. OK TO CONTINUE SERVICE.