MIL-T-62246 Truck, Dump, Street Maintenance, Diesel And Gasoline Engine Driven, 21,000 Pounds Gvw, 4X2, CommericalThis specification covers diesel and gasoline engine driven, four-wheel, two-rear-wheel drive dump trucks equipped with a material sprayer, an auxiliary engine driven air compressor, and a vibrating roller for use in street maintenance. Vehicles shall have a minimum gross vehicle weight GVW of 21,000 pounds for normal operating conditions. Vehicles procured under this specification are commercial items which shall be warranted by the manufacturer as specified in acquisition documents.

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MIL-T-62246B(AT)

3.4.5.1 Clutch. The clutch shall be the largest capacity clutch offered for the vehicle and engine furnished with the clutch torque capacity exceeding the maximum delivered engine torque.

* 3.4.5.2 Automatic or semiautomatic transmission. When specified (see 6.2), the vehicle shall be provided with an automatic or semiautomatic transmission. The transmission shall include a hydraulic torque converter and not less than four forward gear ratios. Normal driving range selector position shall provide not less than four gear ratios without movement of the selector. The transmission shall be provided with SAE J704 power takeoff openings. The input torque capacity of the transmission shall be at least equal to the maximum torque delivered by the engine.

3.4.5.3 Power takeoff. A power takeoff shall be furnished. The power takeoff shall be of a rated capacity to operate powered equipment. Controls to operate the power takeoff shall be located in the truck cab accessible to the seated driver. A caution plate or decal reading "DO NOT OPERATE VEHICLE AT HIGHWAY SPEEDS WITH POWER TAKEOFF ENGAGED" shall be installed so as to be readily visible to the seated driver.

3.4.6 Driveline components. Driveline components shall be adequate to transmit the maximum delivered torque of the engine, as developed through the maximum gear train reduction. The driveline shaft for front mounted winches, when specified in procurement documents, shall have an angle not greater than 16 degrees from the longitudinal plane.

3.4.7 Frame. The chassis frame shall be the manufacturer's standard for the vehicle furnished. The vehicle shall have a frame with reinforcement extending at least from the rear of the front suspension, rear hanger bracket to the front of the rear spring, front hanger bracket. Reinforcement shall provide sufficient structural strength in the chassis frame through increased resisting bending moment to at least equal the load imposed, with the dump body loaded to provide specified GVW. A heavy duty frame with a resisting bending moment of not less than

600,000 inch-pounds may be furnished. Chassis frame rails shall not project beyond the rear end of the body.

3.4.8 Suspension. The vehicle shall be equipped with a suspension system with components having a rated capacity at least equal to the load imposed on each member, measured at the ground, with the vehicle loaded to specified GVW. When suspension capacity is rated at the spring pads, unsprung weight shall be deducted. The vehicle shall be equipped with hydraulic, double-acting shock absorbers at the front wheels.