What was found
(CAN) FOUND BLACKENED, INDICATING OVER-HEAT, YELLOW AND RED TEMP-PLATES ON FWD COUPLING OF MAIN DRIVESHAFT DURING A "TURN-AROUND" CHECK. SHAFT REMOVED, INSPECTED, RE-GREASED, NEW TEMPLATES INSTALLED AND SHAFT RE-INSTALLED. COUPLING OVER-HEATED AGAIN AFTER 1.6 HRS OF OPERATION. SHAFT REMOVED, INSPECTED, RE-GREASED, NEW TEMPLATES INSTALLED. ENGINE REMOVED, RE-SHIMMED IAW DATA FROM LAST AIRFRAME REPAIR JIG, DATA, OCTOBER 1997. ENGINE AND MAIN DRIVESHAFT RE-INSTALLED.