EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES
a. The 5-ton, 6x6, M939, M939A1, and M939A2 series vehicles are designed for use on all types of roads, highways,
and cross-country terrain. These vehicles also operate in extreme temperatures such as arctic weather conditions.
b. The M939 series vehicles are an improved version of the M809 series. The improvements make M939 series
vehicles more reliable and easier to operate. The major improvements are:
This vehicle has been designed to operate safely and efficiently within the limits specified in this TM.
Operation beyond these limits is prohibited IAW AR 70-1 without written approval from the Commander,
U.S. Army Tank-automotive and Armaments Command, ATTN: AMCPEO-CM-S, Warren, MI 48397-
Improved Power Steering System
Complete Airbrake System
Improved Cooling System
Improved Electrical System
Three-Crew Member Cab
Hydraulically Powered Front Winch
c. The M939 series vehicles use 11:00 x R20 tires and have rear tandem duals, while the M939A1 and M939A2
series vehicles use 14:00 x R20 super sized tires and rear tandem singles. The mounted tires and spare on each vehicle
are non-directional in design and use.
d. The M939 and M939A1 series vehicles employ the Cummings (NHC 250) 250 horsepowered engine, while the
M939A2 series vehicles use a smaller, turbocharged Cummings (6CTA8.3) 240 horsepowered engine. The M939A2
series vehicles additionally have the Central Tires Inflation System (CTIS) which allows for greater tactical mobility.
e. All M939/A1/A2 series vehicles utilize the same automatic transmission, are equipped with a spare tire mount at
the rear of the cab, have removable canvas cab tops, and are supplied with pintle hooks and air connections used for
f. The 5-ton load limit rating of M939/A1/A2 series vehicles does not mean these vehicles are limited to 5-ton
payloads. A vehicle rating only indicates the maximum amount of cargo weight the vehicle axles and frame can withstand
when operating under the worst cross-country conditions.