As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GE REPORTS #1 ENGINE ESN 862726 IS EXPERIENCING IN TAKEOFF AND CRUISE FAN VIBRATION. CORE VIBRATION HAS REMAIN STABLE. GROUNDED - YES. ACCOMPLISHED #1 ENGINE FAN LUBE PER TC 78472010. REPLACED 20 SPACERS WITH NEW FROM STOCK. PERFORMED FAN TRIM BALANCE PER B737-900 AMM 71-00-00. BALANCE CHECK GOOD.