As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING FAN LUBE T/C 78472010 ON #1 ENGINE FOUND ALL SHIMS TO HAVE MOLYDAG COATING LOSS BETWEEN 25 TO 100%. GROUNDED - YES. REINSTALLED EXISTING SHIMS DUE NO NEW SHIMS AVAILABLE. SHIMS OK TO REMAIN IN SERVICE REF B737-800 AMM 72-21-02 SECTION L. REPLACE ALL FAN BLADE SHIMS 340-252-307-0 (24) WITHIN 1850 CYCLES.