What was found
(CAN) ON PRE-FLIGHT INSPECTION, GREASE LEAKAGE ON FORWARD COUPLING ON INPUT DRIVESHAFT WAS NOTED. FURTHER INSPECTION REVEALED THATTHE FORWARD SEAL ASSY HAD FAILED AND ALL THE GREASE IN THE FORWARD COUPLING WAS THROWN OUT WHICH CAUSED AN OVERHEAT CONDITION. A MORE DETAILED PRE-FLIGHT INSPECTION OF FORWARD AND AFT SEAL ASSEMBLIES FOR RIPS, TEARS AND GREASE LEAKAGE WILL HELP PREVENT AN OVERHEAT CONDITION OR TOTAL DRIVESHAFT FAILURE