What was found
(CAN) WHILE TRACKING & BALANCING THE MAIN ROTOR SYS THE PILOT & ENGINEER COULD FEEL AN UNUSUAL VERTICAL VIBS,ON THE NEXT FLIGHT UNUSUAL LATERAL VIBS,ENGINEER MADE ADJUSTMENT TO M/R SYS BUT THE READING ONTHEEQUIPMENT STILL READ ROUGH.WHILE RUNNING ON THE GROUND A SIDE PANEL TO THE TRANSMISSION AREA WAS REMOVED.THE ENGINEER ASKED THE PILOT TO ADD A LITTLE POSITIVE COLLECTIVE.IT WAS OBSERVED THAT THETRANSMISSION MOVED UP ABOUT 3/4 OF AN INCH.IT WAS NOTICED THAT THE LIFT LINK WAS BROKEN ON THE UPPER END WHERE IT IS ATTACHEDTO THE TRANSMISSION.