| Mack Model NM | |
| Type: | 6-ton 6x6 Prime mover |
| Is Vehicle: | yes |
| Designer: | Mack |
| Manufacturer: | Mack |
| Production Date: | 1940-1944 |
| Number: | 8,400+ (all models) |
| Spec Label: | NM3[1] |
| Weight: | 22659lb |
| Length: | 23feet |
| Width: | 82NaN2 |
| Height: | 9feet |
| Engine: | Mack EY |
| Engine Power: | 159hp |
| Transmission: | 5 speed x 2 range trf. case |
| Suspension: | Live beam axles on leaf springs |
| Vehicle Range: | 2801NaN1 |
| Speed: | 34mph |
The Mack NM 6-ton 6x6 truck, officially "Prime Mover Cargo truck (G-535)", was Mack's first military 6x6. It debuted as a prime mover in 1940, and was used for towing AA guns, and ammunition. Gun crews rode in its canvas covered bed. The NM's enclosed cab came from the commercial L-model. Many NM's were used by the British as recovery vehicles.
Overall Dimensions:
* 23feet long
* 8feet wide
* 9feet tall
Weight: 21750lb
Engine
Mack EY 7071NaN1 ohv inline 6 cyl. gasoline engine with 170hp at 2100.
Gearbox
Mack TR36 5-speed direct-top
Transfer Case: Timken-Detroit 2-speed T77 with 2.55 low
Wheelbase
14feet
Tires 9.75-22 (NM-1, -2, -3 Lee commercial with highway tread)
The NM-1 and NM-2 had an amidships mounted winch with a capstan head. It had a short steel cargo body 11feet long and 7feet wide. The cargo body had troop seats, a canvas cover, and a spare wheel on the front right side. NM-2 had smaller head lamps and parking lamps on top.
The NM-3 was the last model to have an enclosed cab. It was similar to the NM-1 and NM-2 except for:front pintle for positioning artillery pieces, arched bumper (front pintle under the arche), smaller brush guard, side lights on mudguards, towing hooks on bumper deleted, radiator shell with Mack nameplate.
There was no NM-4, the prototype NN-2 did not go into production.
The NM-5 and NM-6 had a soft top cab with folding windscreen. It had a wooden cargo body with two spare tires at the front right and left. They had some technical detail changes. The only differences between the NM-5 and NM-6 were rifle brackets in the cab and jerrycan holders left of the winch for the NM-6.
NM-7 and NM-8 were like the NM-5 and NM-6. There were only minor detail modifications.Some were equipped with the gun-carriage brake cylinder: this was an air-cylinder from Hanna for the simultaneous actuation (cable operated) of the air brakes of the truck and the mechanical brakes of the gun.