What was found
AIRCRAFT PERFORMED AN UNSCHEDULED LANDING AT HMO AS CONSEQUENCE OF OVERTEMPERATURE ON LEFT CONSTANT SPEED DRIVE (CSD). LEFT CHIP DETECTORS WERE CHECKED, ALL CORRECT. CSD WAS DETECTED OVERFILLED. CSD WAS DRAINED UNTIL CORRECT LEVEL AND LEFT ENGINE RUN WAS CORRECT. CSD TEMPERATURE WAS CORRECT. DURING OVERNIGHT SERVICE, CSD, SEAL, AND HEAT EXCHANGER WERE REPLACED IAW MM 24-10-01, 72-61-59 AND 24-10-03, RESPECTIVELY, TESTED CORRECT.