What was found
(CAN) PILOT WAS PERFORMING DAILY PRE-FLIGHT INSPECTION. HE FOUND GREASE LEAKAGE FROM THE FORWARD PART OF THE MAIN ROTOR DRIVE SHAFT AT THE TRANSMISSION COUPLING. THE GREASE LEAKED OUT OF THE SPLIT/SEPARATED SEAL/BOOT. THE INDICATOR HAS FLASHED OFF ON THE RED ONES. THE M/R DRIVE SHAFT WAS R & R WITH A SERVICEABLE COMPONENT. THE AFFECTED SHAFT WAS DISASSEMBLED & INSPECTED IAW MM. NOTE: THE TOTAL TIME ON THE SHAFT WAS 12064.2. TIME SINCE LAST 600HRE/ANNUAL INSPECTION & RE GREASE IS 58.3. THE COMPANY IS RETIRING THIS DRIVE SHAFT AND INSTALLING A KAFLEX DRIVE SHAFT. ALTHOUGH STILL IN SERVICEABLE CONDITION THIS DRIVE SHAFT WAS NEAR REPLACEMENT OF DRIVE GEARS DUE TO NORMAL WEAR IT HAS BEEN DETERMINED GENERATOR WAS NOT THE PROBLEM. LUCKILY THE FAILURE HAPPENED VERY SHORTLY BEFORE LANDING.