The Ford Model AA truck moved truck design forward
A front view of the Ford Model AA truck.
The Ford Model AA truck debuted in 1927, shortly after the November debut of the Model A automobile. As Albert Mroz writes in The Illustrated Encyclopedia of American Trucks and Commercial Vehicles, “Both vehicles were powered by the same new engine at first. The new engine featured pump-assisted splash lubrication and pump-circulated thermo-syphon cooling and it displaced 200.5 cubic inches. A 10-gallon cowl-mounted gasoline tank fed a Zenith updraft carburetor and a forged steel three-main bearing crankshaft was used along with aluminum pistons. With a 4.22:1 compression ratio it developed 40 hp at 2,200 rpm. A three-speed selective sliding transmission accompanied the new engine.”
Both vehicles had crowned fenders, acorn-shaped headlights and a nickel-plated radiator shell, “distinctive styling features of the Model A and Model AA trucks,” Mroz writes. “The two cabs were shared between the Model A car and the Model AA truck.”
The Model AA truck’s wheelbase was 131-1/2 inches, and compared to the Model A, added substantial frame improvements, heavier front transverse spring, 13- or 15-leaf longitudinal cantilevered rear springs, 20-inch welded spoke wheels, brake improvements and high pressure truck tires. “The power train was also improved,” Mroz writes, “with larger radius rods, two-piece driveshaft and larger worm-gear rear axle. A planetary 2-speed transmission called Dual-High could be ordered coupled to the 3-speed, giving six forward and two reverse speeds. The basic Model AA chassis was priced at $460 ($5,908 today) with an increase to $540 in the spring of 1928 – Ford Motor Company’s 25th anniversary.”
1929 Model AA’s had six-hole ventilated disc wheels in place of the welded spoke type, and by the end of the year the truck’s overall ruggedness was increased. That included scrapping the Dual-High transmission, and making the 4-speed transmission standard. “Also,” Mroz writes, “a heavier spiral bevel rear axle was used, the front axle, radius rods, king pins and spring were strengthened, brakes were enlarged to 14-inch and positive offset five-hole disc wheels were adopted. These were specially designed to be used as duals, which became available in January 1930.” FC