What was found
(CAN) PILOT REPORTED THAT WHEN DESCENDING RAPIDLY, COLLECTIVE BOTTOMED OUT AND RT PEDAL INPUT, THE PEDALS WOULD VIBRATE AND THE AIRFRAME WOULD VIBRATE AND WITH A LITTLE COLLECTIVE INPUT AND LT PEDAL THE VIBRATION WOULD GO AWAY. THE SAME COULD BE INDUCED ON THE GROUND WITH RT PEDAL INPUT AND NR BEEPED TO MAX. UPON INVESTIGATION OF TAIL ROTOR GEARBOX THE OUTPUT SHAFT HAD BROKE OFF WHERE THE INNER RACE FOR THE ALIGNMENT ROLLER BEARING IS PRESSED ONTO THE IB END OF THE OUTPUT SHAFT.