What was found
FLIGHT 5503, SDF TO IAH - UPON GEAR RETRACTION DURING INITIAL CLIMB, THE GEAR WOULD INDICATE FULL UP FOR A FEW SECONDS FOLLOWED BY AMBER HASHED INDICATIONS. THIS REPEATED SEVERAL TIMES ACCOMPANIED BY A LOUD THUMPING. THERE WERE NO CAUTION, WARNING, OR AURAL WARNINGS RECEIVED. THE GEAR WAS EXTENDED NORMALLY WITH CORRECT INDICATIONS AND THE AIRCRAFT RETURNED TO SDF AND LANDED WITHOUT INCIDENT. MAINTENANCE WAS ABLE TO DUPLICATE THE FAULT WITH THE AIRCRAFT ON JACKS AND TRACED THE FAULT TO THE MAIN LANDING GEAR SEQUENCING VALVE. THE VALVE WAS REPLACED AND THE GEAR OPERATED NORMALLY.