What was found
GEAR DOOR OPEN ALERT CAME ON APPROX 10 SEC AFTER GEAR EXTENTION, STAYED ON F/O APPROX 6SEC. PERFORMED AMM 32-33-00-720-801, FUNCTIONAL TEST OF THE LANDING GEAR HYD CONTROL SYS. GEAR RETRACTION, DOOR RETRACT NORMAL, AND ON GEAR EXTENSION, LT DOOR SLOW TO CLOSE. SUSPECT GEAR SELECTOR VALVE DEFECTIVE. R & R LANDING GEAR CONTROL VALVE IAW AMM 32-31-01. OPS AND LEAK CHECK GOOD. NO DEFECTS NOTED.