What was found
#3 ENGINE OIL PRESSURE DECREASED TO 98 PSI IN FLIGHT, AND THEN 38 PSI AT IDLE. "ENG 3 OIL FILTER" EICAS MESSAGE. RAN QRH PROCEDURE, AND SHUT DOWN ENG 3. (<P>COMPLIED WITH POST WINDMILL INSPECTION IAW B747 AMM 72-00-00-206-059-J00, AND FIM TASK 71-00 A07 "ENG 3 OIL FILTER" MESSAGE. NO DEFECTS NOTED, PERFORMED ENGINE RUN PER 71-00-00-962-003-J00. OIL PRESSURE GOOD. ON NEXT ENGINE START PILOTS REPORTED NO OIL PRESSURE RISE. T/S AND FOUND #3 ENG LUBE AND SCAVENGE PUMP SHAFT SHEARED. REMOVED AND REPLACED PUMP IAW 79-21-03. DRAINED AND REPLACED ENGINE OIL, AND FLUSHED ACCESSORY GEARBOX. PERFORMED DRY MOTOR IDLE AND POWER RUN IAW B747 AMM 71-11-00. OIL PRESSURE GOOD. </P>)