What was found
(CAN) CAUSE OF SMOKE ODOR IN CABIN DUE TO OIL CONTAM OF GAS PATH AIRFLOW DUE TO A LARGE NR OF AIR/OIL SEALS HAD EXCESSIVE CLEARANCES, ALLOWING OIL TO ENTER SECONDARY AIR SYS. ENG DID HAVE A SIGNIFICANT AMOUNT OF FRETTING DAMAGE ON COMBUSION COMPONENTS, WHICH INDICATED THAT ENG OPERATED WITH VIBRATION FOR SOME TIME. RETURNED ENG TO SERVICE, ALL WORN AIR SEALS WILL BE REPAIRED/REPLACED BACK TO THE O/H MANUAL LIMITS. NR 4 BEARING HOUSING WILL HAVE ALL PACKINGS & GASKETS CHANGED TO ENSURE NO FURTHER LEAK. FIT BETWEEN LOW COMPRESSOR SHAFT & LOW TURBINE SHAFT WILL BE RESTORED TO AVOID TO POSSIBILITY OF VIBRATION PROBLEMS. ENG WILL BE TESTED.