As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON INITIAL CLIMB OUT OF JFK THERE WAS A SEVERE ENGINE VIBRATION. EMERGENCY DECLARED AND RETURN TO FIELD IMMEDIATELY. EMERGENCY CANCELED AFTER EXITING RUNWAY. EMERGENCY EQUIPMENT WAS STANDING BY BUT DID NOT RESPOND TO AIRCRAFT. THE AIRCRAFT TAXIED TO THE GATE UNDER ITS OWN POWER WITHOUT FURTHER INCIDENT. REMOVED AND REPLACED LH ENGINE.