As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW TO GDL, DURING CRUISE RIGHT ENGINE OIL QUANTITY WENT FROM 12 QUARTS TO 4 QUARTS IN TWO HOURS. OIL PRESSURE AND TEMPERATURE NORMAL. CREW SHUTDOWN RIGHT ENGINE AND LANDED MTY WITHOUT INCIDENT. FOUND NUMBER TWO GEARBOX LEAKING OIL. REPLACED NUMBER TWO GEARBOX. SYSTEM GROUND CHECKED NORMAL OPERATION.