A DC9 ON DSCNT AT 10500 FT DECLARED AN EMER AND DIVERTED DUE TO LOSS OF L ENG OIL PRESSURE AND QUANTITY. CAUSED BY GEARBOX SCREW BACKING OUT. ENG CHANGED.

Narrative

L ENG OIL QUANTITY DECREASED TO 3 QUARTS. 30 MI N OF ATL; I ELECTED TO DECLARE AN EMER AND DIVERT TO ATL. 15 MI N OF ATL WE SHUT DOWN THE L ENG. YYY DISPATCH AND MAINT CTL GAVE ME INSIGHT OF THE 'BIG PICTURE.' MAINT EXPLAINED THE ENG CAN RUN FOR UP TO 9 MINS WITHOUT OIL. WE IDLED THE ENG TILL IT GOT TO THE RED RADIAL THEN WE CAGED THE ENG. ATC GAVE US PRIORITY HANDLING TO ZZZ. THE FIRE TRUCKS WERE STANDING BY. WE LANDED ON THE LONG RWY AND EXITED ALMOST AT THE END. WE CLRED THE ACTIVE RWY; SET THE BRAKES; AND THE TRUCKS INSPECTED THE L ENG. WE GOT THE OK TO TAXI TO THE RAMP. TRIED TO TAXI; BUT THE L #1 OF 4 BRAKES LOCKED. OUR MAINT DEPT PROCEEDED TO TUG US TO THE GATE WITH THE #1 BRAKE UNLOCKED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED; WHEN ON THE GATE; MAINT ADDED 16 QUARTS OF OIL AND RAN THE ENG. THE RPTR SAID MAINT FOUND A SPRING LOADED ADJUSTMENT SCREW BACKED OUT FROM THE OIL PRESSURE REGULATOR LOCATED ON THE REAR OF THE GEARBOX. THE RPTR SAID THE AIRPLANE WAS REMOVED FROM SVC AND THE ENG REPLACED.