LMTV/MTV M1078 Door Lock Mechanism This is the lock block mechanism for the FMTV series of vehicles. This part fits the left (drivers side) for trucks with forward pull or up pull handles. This part fits the right side (passenger side) for trucks with pull down handles. This piece wears out internally and causes undue stress on the outside door handle and causes it to break. NSN 3040013757322 BAE Systems Part number 12417476