General Motors Corp., Pontiac, Michigan.

Excerpt from Encyclopedia of American Farm Tractors

By: C.H. Wendel

William C. Durant, chairman and majority stockholder of General Motors Corporation was determined to meet the Fordson challenge by getting into the tractor business. If nothing else, it was a face­ saving move. It wasn’t bad enough that Ford had nearly cornered the automobile market — now in 1918, he introduced the Fordson tractor and was threaten­ ing to do the same thing in the farm tractor market.

The obvious response was to challenge Ford in the tractor business. In 1918, GMC purchased a plant at Janesville, Wisconsin, and in August of that year the tractor operation was separately incorporated as the Janesville Machine Company with an authorized capitalization of $2 million dollars. A second plant was erected in 1919 at a cost of $500,000.

Prior to purchasing the Janesville site, GMC bought out the Samson Tractor Works, Stockton, California. Samson had developed a “Sieve-Grip” tractor. It im­pressed the GM people, and after slight modifications, the GMC Samson tractor appeared. Its $1,750 list price was no competition to the Fordson, so in December, 1918, GMC announced “a tractor and a price”. The tractor was the Samson Model “M”, and the price was $650.

By January, 1919, GMC announced plans for a Sam­son Model “ A ” tractor, capable of pulling three plows. Probably due to a lack of capital, the Model A was never put into production.

The Samson Model D, Iron Horse was announced in January, 1919. GMC bought out rights to the “Jim Dandy” motor cultivator, and proceeded to build the Iron Horse in quantity. Motor cultivators were the rage of the day, and GMC obviously hoped to realize excellent profits. The combination of post-war depres­sion and fierce competition, compounded with a poor tractor helped put GMC out of the tractor business. Mechanical problems abounded, and the design was such that the machine could be easily upset. Although some authorities have it that the rein-drive feature led to the downfall of the Iron Horse, it should be noted that the rein-drive system provided coordinated move­ment between hands and feet — a feature not found on most motor cultivators.

GMC experienced huge losses in its Samson ven­ture. The small profits from the Model M were more than eaten up by the losses from the Iron Horse. By 1922, GMC got out of the tractor business and con­verted the Samson plant into a Chevrolet assembly operation.


General Motors Corporation waltzed into the tractor business with the Samson Sieve-Grip tractor. Priced at $1,750, it was too high priced to compete with the Ford- son, and was soon replaced with the Samson Model M. A GMC four-cylinder 4% x 6 inch engine provided 12 drawbar and 25 brake horsepower. The special sieve grip rear wheels were of special value on loose or sandy soil. Remy starting and lighting equipment was available as a customer option. The Sieve-Grip was available through 1919.


GMC opted for the motor cultivator business by buying out the manufacturing rights to the Jim Dandy motor cultivator. Immediate plans were made to flood the market with the Iron Horse. There was no transmission clutch. The transmission was through belts and pulleys with independent clutch control for each side of the trac­ tor. A Chevrolet 3 “/i« x 4 inch engine provided the power. Weight was 1,900 pounds, and the 1920 price was $450. Poor design, market resistance, and lack of capital all contributed to a hasty abandonment of the Iron Horse tractor.
The Samson Model M was announced in December, 1918. At $650, it provided excellent competition for the Ford- son, since the Samson was sold complete with platform, fenders, governor, belt pulley, and other features. These were all extras over and above the base price for the Ford- son. After adding up the figures, the Samson ended up be­ ing an excellent tractor for the money. The Northway engine had a 276 CID. Clutch was a multiple disk type, running in oil. The transmission and rear axle were built as a unit. Shipping weight was 3,233 pounds.