The M939 series truck is a 5 ton (10,000 pound) 6x6 US Military truck that was developed to replace the M39 and M809 series of trucks. It is capable of carrying it's design load over all terrain and in all weather. A number of specialty bodies were produced. An estimated 44,590 units were produced. This is the operator manual. It is being reprinted as a convenience to operators, enthusiasts and private owners.