What was found
98-0133, NR 1 OIL QTY WAS 16 QTS ON GRND AT LEVEL OFF FL 310 12 QTY. STARTED TIMING THE DROP AT 7 QTS, LOST 1 QT PER 7 MIN. PRECAUTIONARY LANDING IN DEN. WHEN WE LANDED ANALOG AND ECAM SHOWED 4 QTS. REMOVED WASHER LODGED BETWEEN SEAL AND AFT CASE OF TOWER SHAFT GEAR BOX. LEAK CHECKS OK. SERVICED WITH 11 QTS OIL.