What was found
EN ROUTE NR 2 ENG OIL DROPPED FROM 6.7 GALLONS TO 3.9 GALLONS BY TOC. OIL QTY CONTINUED TO DROP AT A RATE OF 1.4 GALLONS IN 1ST HOUR OF CRUISE. ALL OTHER PARAMETERS NORMAL. AN EMERGENCY WAS DECLARED, DIVERTED TO NRT. FUEL DUMP WAS PERFORMED TO LAND AT MAX LANDING WT & WAS UNEVENTFUL. ACCOMPLISHED NR 6 TEST STATIC LEAK CHECK IAW MM 71-00-00. NO OIL FOUND IN 3.5 BLEED. CHECKED OIL FILTER MAIN CHIP DETECTOR ANGLE GEAR BEARING 3 & 4 TOWER SHAFT 1/2 BEARING DE-AERATOR. REMOVED CSD GENERATOR & INSTALLED DISPATCH EQUIPMENT. CONDUCTED NR 2 ENG HI POWER RUN EPR 1.32 FOR 15 MIN. VISUALLY INSPECTED & FOUND NO OIL LEAKS. FURTHER INSPECTION REVEALED A CRACK IN THE INTERMEDIATE CASE. ENGINE REMOVED & REPLACED.