As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE REMOVED DUE TO IMPELLER CYCLES: TURBINE DISASSEMBLED DUE TO N1 DRAG ON TEST CELL. UPON INSPECTION OF TURBINE PARTS NOTED: SPLINE WEAR BEYOND SERVICEABLE LIMITS ON N1 COUPLING SPLINE (FAILED NO GO GAUGE) INSTALLED A NEW N1 COUPLING.