MIL-T-62491 Trucks, Wrecker: 4540 To 40 820 Kilograms 5-Ton To 45-Ton Lifting Capacity, Modified CommercialThis specification covers all commercial, non-tactical wreckers procured for military use. 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-62491C

"DO NOT OPERATE VEHICLE AT HIGHWAY SPEEDS WITH POWER TAKEOFF ENGAGED" shall be installed so as to be readily visible to the seated driver (see 3.1.1.13). For class 10 vehicles with an automatic transmission, a split shaft power takeoff or an engine driven hydraulic system with an electric, asbestos free, clutch shall be provided.

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.

* 3.4.7 Frame. The truck frame reinforcement or heavy duty frame shall be in accordance with the wrecker body manufacturer's recommendation for the size of wrecker unit furnished. Chassis frame rails shall not project beyond the rear end of the body. For all but class 10 wreckers, the chassis shall have a heavy duty main frame or frame with reinforcement extending at least from

the rear of the front suspension rear hanger bracket to the bogie trunnion mounting bracket. The heavy duty frame shall have frame rails of greater section modulus than the manufacturer's standard for the class of vehicle furnished and shall provide structural strength at least equivalent to the reinforced frame specified herein. Reinforcement shall provide sufficient structural strength in the chassis frame through increased resisting bending moment, to at least equal the loads imposed with the vehicle loaded to the most severe loading configuration allowed by table X, XII or XIII.

3.4.8 Suspension. The vehicle shall be equipped with a suspension system with components having a rated capacity at least equal to that specified in 3.2.5. When spring capacity is rated at the spring pads, unsprung weight shall be deducted.

* 3.4.9 Axles. Axle ratings shall be at least equal to that specified in 3.2.5. The front and rear axles on model 4x2 and 6x4 and the rear axles on model 4x4 and 6x6 shall have oil lubricated wheel bearings and axle spindles. Provisions for venting or withstanding pressure buildup and for replenishing the oil supply shall be provided.

3.4.9.1 Rear bogie. The rear bogie on model 6x4 and model 6x6 vehicles shall be of the four- wheel type, complete with axles, springs, torque rods, and all other necessary parts. The bogie shall be provided with means permitting differential action between the two axles and a manually

or automatically controlled lockout assuring equal power to each rear axle. The manual lockout control shall be located in the truck cab. The axle gear ratios shall provide the performance specified in 3.3 through 3.3.1.3.

3.4.9.2 Two-speed axles. When specified for model 4x2 or 6x4 (see 6.2), a two-speed axle shall be furnished, equipped with electric, vacuum, or air shift and provided with ratios which will permit proper gear splitting. The gear ratios shall provide the performance specified in 3.3 through 3.3.1.3.