What was found
PRECAUTIONARY SHUTDOWN NR 4 ENGINE AT 0308Z, FL300 DUE TO LOSS OF OIL QTY, ENGINE WAS STABLE WITH 3 QUARTS OIL AT SHUTDOWN WITH NO OTHER EXCEEDANCES. WINDMILLED 189 MINUTES AT 12 PSI, WINDMILLED 9 MINUTES BELOW 10 PSI. ENGINE 4 WAS SHUTDOWN IAW QRH. PERFORMED ENGINE POST WINDMILLING INSPECTION IAW MM 72-00-00. CLEANED OIL FROM ENGINE. PERFORMED EXAMINATION FOR OIL LEAKAGE IAW MM 79-00-00. FOUND EXCESS OIL ACCUMULATING AROUND AND ON IDG QAD RING. SUSPECT BAD IDG SHAFT SEAL. R & R IDG SHAFT SEAL IAW AMM 24-11-01. OPS AND LEAK CHECK IS GOOD.