What was found
(CAN) A/C EXPERIENCING REOCCURRING PROBLEMS WITH TORQUE IND. & RUDDER BOOST RELATED SYSS OVER PERIOD OF 30 DAYS. SEVERALATTEMPTS TO CORRECT VIA CLEANING & REPLACING OF EXTERNAL COMPONENTS WERE COMPLETED & TEMPORARILY CORRECTED PROBLEMS ON EACH ATTEMPT.AFTER EXHAUSTING ALL POSSIBLE EXTERNAL CONTRIBUTORS, ENGINE SPLIT AT "C" FLANGE & FROM PT DISC FWD TO "A" FLANGE, DISASSEMBLIED TO ACCESS TORQUEMETER VALVE. VALVE FOUND TO BE ERRODED OR GROUND DOWN BY APPROX 0.125 INCH. ALLOWED PORTING OF OIL AT UNSPECIFIC & UN-CNTLLED TIMES. "SWARF" BEING CREATED BY GRINDING EFFECTS ALSO MOVING ABOUT CAVITY & CAUSING SPORATIC EFFECTS OF PISTON MISALIGNMENT WITH OIL PORTS.