What was found
GEAR DOWN DISAGREE, LT MAIN NOT DOWN. TURNED ON HYDRAULIC 2 & 3 PUMP PER QRH. CYCLED GEAR, GOT ALL GEAR DOWN & GREEN. FLT#6436 REPLACED MLG SELECTOR VALVE IAW AMM. PN ON/OFF75000500, SN ON 0047T, SN OFF 0013T, PN ON/OFF 17051-101, SN ON DCL073-93 & SN OFF CWDD2153-02.