What was found
PIT - FLT 79 - INBOUND, CREW RECEIVED LOW OIL PRESSURE INDICATIONS VIA EICAS MESSAGE AND AMBER LIGHT FOR THE LEFT ENGINE. CREW SHUT DOWN ENGINE. FLIGHT CONTINUED TO PIT AND LANDED WITH NO FURTHER INCIDENT. (SET 20 MINUTES). MAINTENANCE REPLACED THE GEARBOX. TEAR DOWN OF THE GEARBOX REVEALED THE SPLINED DRIVESHAFT WHICH CONNECTS THE OIL PUMP AND FUEL PUMP GEARS WAS SEVERELY WORN. THIS CAUSED LACK OF DRIVE TO THE OIL PUMP RESULTING IN LOSS OF OIL PRESSURE. (X)