As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BNA - INFLIGHT EWR-DFW. CREW REPORTED RIGHT CONSTANT SPEED DRIVE OIL QUANTITY LOW. SHUTDOWN RIGHT CSD WITH LEFT CSD ON MEL EMERGENCY WAS DECLARED. FLIGHT DIVERTED BNA LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND BAD O-RING ON CSD FILL PORT. REPLACED RIGHT CONSTANT SPEED DRIVE AND GENERATOR. SYSTEM GROUND CHECK NORMAL OPERATION.