What was found
PILOT REPORTED DURING DEPARTURE FROM DFW, THE 'GEAR NOT LATCHED' LIGHT ILLUMINATED. THE ALTERNATE GEAR/DOOR WARNING SYSTEM INDICATED THE MAIN GEAR DOOR CLOSED. WE PERFORMED THE 'GEAR/DOOR NOT LATCHED LIGHT' ILLUMINATED CHECKLIST AND HAD TO CYCLE THE GEAR 2 TIMES BEFORE SUCCESSFUL UPLATCH CHECK. FOUND LOCKING TAB SHEARED AND LOCKING NUT LOOSE AND NOT SAFETIED ON LEFT GEAR DOOR UPLATCH CYL. FOUND LEFT GEAR DOOR UPLATCH MECHANISM OUT OF RIGG. ALSO, RT GEAR DOOR UPLATCH PROX SWITCH WAS LOOSE. COMPLETED MM PROCEDURE 32-31-04. OPS NORMAL (P/N 4648615-5503, NAS513-7).