What was found
LEFT MLG FAILED TO RETRACT AFTER TAKE-OFF, GEAR PINS INSTALLED & ALTERNATE MLG DOWN SWITCH IN ALTN POSITION. OK TO CONTINUE IAW MEL 32-16-01. SP1 C/W. REMOVED LT MLG DOWNLOCK ACT IAW AMM 32-32-51. C/BS PULLED & COLLARED IAW AMM 32-09-00-840-801. HYD SYS A & B RESERVOIRS DEPRESSURIZED & HYD QUICK DISCONNECTS DISCONNECTED IAW AMM 32-32-51. MLG PINS INSTALLED IAW AMM 32-00-01. PARTIALLY LH MLG DOWNLOCK ACTUATOR PER AMM 32-32-51. INSPECTION FOUND MISSING WASHER ON DOWNLOCK ACTUATOR HEAD PIN BUILD UP. AOG ON WASHER. INSTALLED LH MLG DOWN LOCK ACTUATOR IAW AMM 32-32-51. OPS/LEAK CHECK GOOD.