TM-5-3805-274-13-P

OPERATOR MAINTENANCE

THEORY OF OPERATION

GENERAL

This work package describes components of the M917 Dump Truck and is provided to give the operator and

maintenance technician a basic knowledge of the equipment prior to its use. A description of component is

provided below.

M917 DUMP TRUCK BODY

The M917 Dump Truck Body consists of a steel dump body designed for transporting and dumping hot

asphalt, aggregate, or similar materials.

M917 DUMP TRUCK HYDRAULIC SYSTEM

The M917 Dump Truck has a sealed closed-loop hydraulic system for lifting and lowering the dump bed. The

hydraulic system operates on pressure supplied by a hydraulic gear-driven pump mounted directly to the

vehicle PTO. The dump bed has a double-acting tailgate that hinges at the top and may be adjusted to regulate

the rate at which material is dumped when the bed is raised. A tarpaulin is provided to cover the bed while in

transit. The following paragraphs describe each system’s function and identify major components within the

system.

DUMP BED

The dump bed is constructed of 8 gauge steel without intermediate crossmembers or vertical stiffeners. The

ﬂoor is of ¼-inch HTLA steel. The dump bed tailgate is slanted and pin hinged at the top with locking

jaw/hinge mechanism at the bottom. The locking mechanism is mechanically linked to a control lever mounted

on the side of the dump bed, near the driver door of the cab. The control lever, when pulled forward and

down, releases two jaws that are locked over large pins at the bottom of the tailgate. This allows the tailgate to

swing out at the bottom when the dump bed is raised. Raising the control lever locks the jaws over the large

pin and prevents the tailgate from opening. With the control lever locked, the top hinge pins may be removed

and the tailgate lowered to a level determined by the placement of the adjustment chain. This allows the

operate to haul items too long for the bed, such as long curb forms, etc. A chain threaded through bracket-type

eyelets across the tailgate may be adjusted in length to regulate the maximum opening of the tailgate. A dog

house, inside the dump bed at the front, houses the top of the hydraulic cylinder and provides an attaching

point to the dump bed.

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