EQUIPMENT DESCRIPTION AND DATA
EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES
The M917, Dump Truck, 20-Ton, 8X6 provides the capability of hauling, dumping, or spreading heavy loads
of hot asphalt, aggregate, dirt, and similar materials. The M917 vehicle chassis has off-road capabilities
providing a wide variety of terrain in which the dump truck can operate. The dump truck contains a sealed
hydraulic system for raising and lowering the dump bed. The hydraulic system is powered by the vehicle
chassis PTO unit. The tailgate can be adjusted for dumping the load or for controlled spreading while the
vehicle is moving.
LOCATION AND DESCRIPTION OF MAJOR COMPONENTS
Figure 1 shows the location of major dump truck body components you will need to become familiar with to
operate the M917 dump truck.
This steel rod, bolted to the cab protector, provides the operator a visual indication of when the bed is down.
This is a rectangular shaped steel bed for hauling hot asphalt, aggregate, or various other materials. It
incorporates a cab protector as a structurally integral component. Its purpose is to protect the cab. A dog house
is provided in the front of the bed in which the hoist cylinder is mounted.
There are 14 hooks attached to the dump body for attaching the tarpaulin, five on each side, two in front, and
two in the back.
This is a double-acting tailgate that is hinged at the top and bottom. For normal operation, the tailgate is
hinged at the top and opens outward at the bottom. A locking mechanism, operated by the tailgate control
lever, is provided to lock the tailgate in the closed position. When the control lever is up, two jaws, one on
each side of the tailgate, clamp over the large pins or rods at the bottom of the tailgate. By removing the top
pins and lowering the tailgate from the top to a level position and securing with the adjustment chain, extra
long materials can be hauled.
Allows adjusting the maximum swing travel of the tailgate for spreading. This is accomplished by shortening
or lengthening the linkage of the chain.
When the bed is raised for purposes of inspection or other maintenance, the safety strut should be raised as a
safety precaution. The safety strut is hinged at the back and when raised, forms a cradle with the cross
member braced across the bottom of the bed. When not in use, it rests between the chassis frame rails.
HYDRAULIC CONTROL VALVE
This is a single-spool valve with the control piston mechanically linked to the hydraulic control lever in the
cab. It supplies hydraulic pressure to raise and lower the dump bed.
This is a three stage telescoping cylinder that, under hydraulic pressure, raises the dump bed. The cylinder
piston is attached to the dump bed inside the dog house and the cylinder base is attached to the dump body
subframe. In the lowering cycle, pressure is relieved through the pilot valve which allows the cylinder to
compress under the weight of the dump bed.