What was found
(CAN) ENG SHUTDOWN IN FLT DUE TO TORQUE FLUCTS & LOW OIL PRESS. 6 BOLTS USED TO ASSEMBLE 1ST STAGE CARRIER ASSY. 2 OF 6 BOLTS FAILED DURING OPS. 1 BOLT HEAD FOR 1ST STAGE CARRIER ASSY FRACTURED IMMEDIATELY UNDER BOLT HEAD. HEAD OF BOLT LODGED INTO 1ST STAGE REDUCTION GEAR TRAIN, RESULTING IN DEBRIS & FRACTURING OF 1ST STAGE RING GEAR. DEBRIS IN LAST CHANCE FINGER STRAINER IN RGB, PREVENTING OIL SCAVENGING. RESULTED IN RGB FILLING WITH OIL, & NO OIL BEING RETURNED TO REPERISH OIL TANK. OIL TANK RAN LOW ON OIL CAUSING LOW OIL PRESS. TORQUE FLUCTS RESULT OF DAMAGED RING GEAR & LOW OIL PRESS. 2ND BOLT FRACTURED IN ASSY, BUT STAYED IN ASSY & DIDN`T CAUSE SHUTDOWN. BOLTS WERE RE-INSTALLED DURING OVERHAUL.