What was found
(CAN) IMMEDIATELY AFTER DEPARTURE DURING CLIMB, THE ACFT EXPERIENCED ENGINE VIBRATIONS FROM THE NR 1 ENGINE. THE FLIGHT LEVELED OFF AT 13,000 FT AND THE VIBRATIONS SUBSIDED. THE CREW RECOMMENCED THE CLIMB TO 17,000 FT WITH THE VIBRATION RETURNING. THE CREW ELECTED TO RETURN TO AIRPORT AND LANDED. ENG N1 BALANCE IEVM METHOD CARRIED OUT IAW AMM 72-21-00-750-801-A.