What was found
BOTH CONTROL YOKES BEGAN SHAKING/VIBRATING DURING CLIMB OUT, AS WE ACCELERATED FROM ~ 210-240 KNOTS. IT THEN STABILIZED, UNTIL RANDOMLY RETURNING IN CRUISE AT 70KTS. REMOVED FROM SERVICE. C/W CHAPTER 5 INSPECTION FOR EXCESSIVE/UNUSUAL VIBRATION. PERFORMED PROP BALANCING OF #1 & #2 PROPS, FOUND #1 PROP BALANCE OUT OF LIMITS, PERFORMED 6 BLADE RETORQUE OF #1 PROP. FOUND #5 BLADE RING NUT MOVEMENT OUT OF LIMITS. R & R #1 PROP # 5 BLADE BORE LINER, OPS TEST NORMAL. NO SHAKING/VIBRATION NOTED IN CONTROL YOKES. NO FURTHER DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.