What was found
FLAPS FAIL AMBER CAS: AMBER FLAPS FAIL CAS MESSAGE AFTER TAKEOFF. FLAPS STUCK AT 13 DEGREES RESET FLAPS, AFTER RESET FLAPS WOULD MOVE HOWEVER WOULD MAKE A LOUD RUMBLE AT AROUND THE 13* MARK. CW FLAP LUBE PROCEDURE IAW AMM 12-20-04. NO HELP. REMOVED LT INBD FLAPS OTBD ACTUATOR FLAP COVE PANEL & CONFIRMED SOUND WAS COMING FROM ACTUATOR, REMOVED BALL NUT SIDE OF ACTUATOR AND MOVED IT THROUGH ITS STROKE. NOTED A ROUGH SPOT AT THE TOP OF TRAVEL. .REMOVED LT WING INBD FLAP, OUTER REMOVED LT WING INBD FLAP, OUTER ACTUATOR. INSTALLED A REPAIRED FLAP ACTUATOR IAW AMM 27-53-01. LUBED, RIGGED AND ADJUSTED FLAP ACTUATOR PERFORMED SYS CHK OF FLAP SYS, SATISFACTORY RESULTS ALL IAW AMM 27-53-01.