The Ford Model TT is a truck made by the Ford Motor Company. It was based on the Ford Model T, but with a heavier frame and rear axle, giving it a rating of 1 short ton (0.91 t).
The rear axle of the TT had a worm drive and crown wheel, unlike the Model T's crown wheel and pinion. The worm was located at the end of the drive shaft and above the crown wheel. The wheelbase of the Model TT was 125 inches (3,200 mm), compared to 100 inches (2,500 mm) for the Model T. It was often equipped with an accessory gearbox, such as the Ruxtell or Jumbo gearboxes, which allowed the truck to have intermediate gears between low and high, useful for hill climbing. It was often sold as a chassis with the buyer supplying the truck body as needed. Mass production with Ford produced bodies ran from 1925 to 1927, but production of the Model TT had started with the first chassis being released in 1917. In 1923, it cost $380. In 1925, a hand operated windshield wiper was added.
It was very durable for the time, but slow when compared to other trucks. With standard gearing, a speed of not more than 15 mph (24 km/h) was recommended, and with special gearing, a speed of not more than 22 mph (35 km/h) was recommended, according to Ford Dealers Data Book 1923. Standard worm gear ratio was 7.25:1, and special gearing gave a ratio of 5.17:1. Because of this, accessory catalogs offered items to help give the Model TT more power.