As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENGINE, MAIN ROTOR DRIVE SHAFT HAD 10 CRACKED DISCS ON FORWARD DISC PACK. DISC PACKS WERE REPLACED ON BOTH ENDS OF DRIVESHAFT. THE ENGINE TO TRANSMISSION DRIVESHAFT ALIGNMENT WAS CHECKED AND FOUND TO BE WITHIN LIMITS. A VIBRATION CHECK WAS RUN ON THE TRANSMISSION INPUT SECTIONS AND FOUND TO BE OK.