Figure 100. — Model of 1921 Autocar truck, type XXVI-Y. This quarter-scale 

 model represents a vehicle with a 120-inch wheelbase. 



The rear axle is of the full-floating, double-reduction, 

 gear-driven type, the gear reduction being compounded 

 through bevel and spur gears. This construction allows 

 low reduction without the sacrifice of road clearance. It 

 also reduces the angularity of the propeller shaft, giving 

 straight lines for the transmission of power. All the gears 

 in the rear axle are of heat-treated steel carried on adjust- 

 able, tapered, roller bearings. The complete gear train is 

 mounted on a cover plate bolted to the axle housing. This 

 cover plate and gear train can be removed as a unit from 

 the axle housing for inspection and adjustment purposes. 

 The rear wheels are mounted on adjustable, tapered, roller 

 bearings carried on an extension of the axle housing. By 

 this means the rotating parts of the rear axle carried no part 

 of the weight of the truck, their only function being to trans- 

 mit the power to the rear wheels. The driving axles are 

 of heat-treated alloy steel. The rear tires, of solid rubber, 

 are 36 by 10 inches. 



The engine and clutch are in one unit, which is carried 

 in the frame by means of 3-point suspension under the seat 

 structure. The engine is a 4-cylinder, 4-cycle, water- 

 cooled unit of 4 1 /4-inch bore and SV^-inch stroke, with a rated 

 horsepower of 28.9. It is equipped with a counterbalanced 

 crankshaft of heat-treated alloy steel mounted on two ball 

 bearings. 



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