What was found
DURING CLIMB THE THE FLIGHT CREW GOT AN LANDING GEAR/AIR FAIL EICAS MESSAGE AND THE LANDING GEAR FAILED TO RETRACT. CREW DECLARED AN EMERGENCY AND RETURNED TO ORD. MAINTENANCE INSPECTED THE AIRCRAFT, AND THE AIRCRAFT WAS FERRIED FROM ORD TO STL GEAR DOWN. MAINTENENCE INSPECTED AND REMOVED AND REPLACED THE LANDING GEAR LEVER, LEFT MAIN LANDING GEAR PROX SWITCH, REPAIRED WIRING ON THE NLG WOW PROX SWITCH, REPINNED THE LEFT MLG WOW PROX SWITCH CONNECTOR. GEAR SWING CHECKED GOOD. AIRCRAFT FLEW A MAINTENANCE TEST FLIGHT THAT INCLUDED THREE TAKEOFFS AND LANDINGS. MAINTENANCE CHECK FLIGHT WAS GOOD.