Prior to and during World War II the United States Army called several tractors M1 light tractor. Under the Ordnance Corps these commercial off-the-shelf tractors were meant to tow artillery pieces so were not equipped with blades like their Engineer counterparts. Eventually these were replaced by purpose-built high-speed tractors (HSTs). Some tractors were equipped with crane attachments for ammunition, and material handling.

TB 5-9720-11 (1944) gives the following detailed information:

TRACTOR, CRAWLER, DIESEL, 35 TO 40-DBHP, STANDARD, CATERPILLAR, D4

Manufacturer: Caterpillar Tractor Co. Stock No.: 78-8138.0-44 Peoria, Illinois Model: D4

1. General. — The D4 is designed for towing and all types of general construction work. Accurately located frame-holes are provided for attaching varied tractor equipment to adapt it for use in earth moving, road clearance, and airport construction work.

2. References. — For further information regarding this equipment, refer to: TM 5-3110; ASF Catalog, Section ENG 7-T31, ENG 8-T31.

3. Engine. — Make: Caterpillar. Model: D4. Fuel: Diesel commercial. Cylinders: 4. Bore and Stroke: 4}£ x 5K-in. Governed speed: 1400 rpm. Valve adjustment: 0.010-in. Firing order: 1-3-4-2. Equipped with Independent, 2-cylinder, 4-stroke-cycle gasoline starting engine.

4. Fuel, coolant, and lubrication data. — Fuel tank: 25-gal fuel oil. Radiator: 11 -gal water. Crankcase: 4-gal engine oil. Transmission: 5-gal gear oil. Final drive cases: 1%-gal gear oil each. Engine oil grade: OE-30 above 32 F, OE-10 below 32 °F. Gear oil grade: GO-90 above 32 F, GO-80 below 32 °F.