The Allis-Chalmers Models H4-HD4 Crawler Tractors

The concept and design approach to the Allis-Chalmers H4-HD4 crawler tractor led to a general purpose machine capable of being used with attachments such as a one yard loader, dozer, scarifier, and logging equipment. The general arrangement is different due to a midmounted radiator and some repositioning of operator controls. Many items, including a torque converter drive and a power shift Shuttle Clutch, were evaluated in regard to function, comfort, and convenience.