MIL-T-62320 Trucks, Van: Shop, Diesel And Gasoline Engine Driven, 19,000 Pounds Gvw, 4X2 And 4X4, CommercialThis specification covers diesel and gasoline engine driven, four-wheel, two-rear-wheel drive, and four-wheel, four-wheel drive, shop van trucks having a minimum gross vehicle weight GVW of 19,000 pounds for normal operating conditions. Vehicles procured under this specification are commercial items which are warranted by the manufacturer as specified in acquisition documents.

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MIL-T-62320C

3.3.1  Speeds and gradeability.  High and low speed requirements shall be met with the vehicle loaded to the specified GVW.

3.3.1.1  High speed gradeability.  The vehicle shall ascend a continuous grade of 1.5 percent at 50 miles per hour (mph).  Gradeability requirements shall be met with the main transmission in direct drive and, when a multispeed axle is furnished, with the axle in high speed range. Gradeability shall be verified with calculations in accordance with SAE J688 (see 6.3).

*    3.3.1.2  Low speed.  Low speed for vehicles equipped with a manual transmission shall be calculated with the engine operating at not less than 35 percent of the recommended governed speed, and shall provide not more than the vehicle speed (mph) specified in table I for the corresponding number of available forward speeds.

TABLE I.  Vehicle low speed requirement.

*    3.3.1.3  Maximum geared speed.  The maximum geared speed at engine governed speed shall be not less than 58 mph for model 4x2 vehicles and 55 mph for model 4x4 vehicles.

Conformance to geared speed specified shall be determined by calculations made in accordance with the following formula:

Maximum geared speed (mph)=                 Governed speed (rpm)         Total gear reduction x tire factor (see 6.3)

3.3.2  Service brakes.  The service brakes shall control and hold the vehicle when loaded to its specified GVW on a 30 percent grade.  The service brakes shall stop the vehicle, loaded to specified GVW, within the stopping distance requirements of Federal Motor Carrier Safety Regulation 393.52.

3.4  Chassis components.

3.4.1  Engine.  The engine furnished shall be the chassis manufacturer's standard or optional engine for the commercial model truck which meets or exceeds the requirements of this specification.

*    3.4.1.1  Diesel engine.  Unless otherwise specified (see 3.4.1.2), the vehicle shall be equipped with a liquid cooled, compression ignition, two-stroke or four-stroke cycle diesel engine with not less than four cylinders for 4x2 model and not less than six cylinders for 4x4 model vehicle. Engine net horsepower used in performance prediction calculations shall be determined in

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