Model T Fords Converted Into Tractors

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Front cover of a 1917 Forma-Tractor brochure showing a satisfied farmer washing up with his plowing finished — thanks to his trusty Model T roadster and Forma-Tractor attachment.
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A Knickerbocker-equipped Ford pulling a 6-foot single disc harrow and 2-section spike-tooth smoothing harrow.
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Rear view of the Forma-Tractor on a Ford roadster.
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A cut-down Model T Ford with an unknown make of tractor conversion, maybe Sears or Montgomery Ward.
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This “simple one-man control” was touted as a way for one man to control both the Forma-Tractor and a horse-drawn implement.

Henry Ford made more than 15 million Model T Fords from 1908 to 1927; the things were everywhere. It’s no wonder some folks dubbed the sturdy little car the “mechanical cockroach,” or that there were lots and lots of them available for converting into all sorts of uses besides basic transportation. (For more, see Ford Model A on Snowshoes by Bill Vossler.)

Lots of Model T Ford cars were converted into trucks, often by using aftermarket kits that provided extended frames and heavier duty rear ends. It didn’t take long for inventors and tinkerers to see the possibilities of adapting the Tin Lizzie into a more or less serviceable farm engine for pulling the horse-drawn implements that every farmer then had, even though some experts said the Ford was entirely unsuitable.

As Bascom B. Clarke, editor of Gas Review magazine, wrote in the June 1917 issue: “No Hiram, you can’t make a real tractor out of an automobile any easier than you can make a draft horse out of a jack rabbit.” And: “Can the leopard change his spots or the Ethiopian his skin? Well, then, why should anyone expect to make a real tractor out of an automobile unless, to quote scripture again, he has first looked upon the wine when it was red?” In the July 1917 issue, he observed: “Take it from me, Hiram, a tractor is something different yet from a tin Henry with tractor wheels on the hind end.” And: “Those people who think they can turn a Tin Lizzie into a real tractor with a few gears and a yard of hay wire are going to wake up one of these days and wish they had their money back.”

Despite such caveats, several companies sold kits to make these conversions — Staude Mak-A-Tractor, Sears, Roebuck & Co., Montgomery Ward & Co., Pullford and Shaw were possibly the best known — but this is about a conversion kit that I heard of only recently, the Knickerbocker Forma-Tractor.

Labor-saving solution

In the years before World War I, Walter C. Guilder, who was born in 1877 in Toledo, Ohio, was trained as an engineer and worked for Kelly-Springfield Motor Truck Co., Springfield, Ohio. Guilder owned an 80-acre farm near Toledo, Ohio, that was run by his brother and powered by horses. Walter made frequent visits to the farm and observed that it was necessary to keep four horses and two hired men to do the work and that there was at times not enough work to occupy them, while in busy seasons they were unable to keep up.

By 1916 they had almost decided to buy a tractor, but found that not only would it cost about $1,200 (about $25,750 today) to buy something reliable, but they “were puzzled as to which one of the many offered to buy.” Walter writes: “On the streets of Springfield I often saw a number of Ford cars with truck attachments … carrying as high as 2 tons [and even] pulling a 4-ton van.” He goes on, “My brother had a Ford car, and it occurred to me that I could just as well build him a tractor attachment to pull plows, harrows and all other implements, and wagons. That was long before anyone thought of tractor attachments.”

At first Walter thought it would be an easy job, but found that he needed all his 14 years’ experience (he had worked for both Mack and Garford truck companies prior to Kelly-Springfield) in mechanics and motor construction to figure the thing out. “I was not building [it] to sell, but for my brother to use, so it had to be right,” he wrote.

When the machine was finished and put to work, the brothers found that, “The device itself was simple and perfect, but the Ford engine had a tendency to overheat.” Walter finally solved the overheating problem and “… the machine was fit to do all of my brother’s work as well as any high priced tractor … and a lot of work which large tractors could not touch.”  

So, the brother got rid of one man and one team and was then able to do all the work on time, plus additional work that had previously gone undone. Soon a neighbor asked Walter’s brother how he could get a similar attachment, so Walter built one for him. The proverbial light bulb went on over Walter’s head and he decided to manufacture his attachments for sale to other farmers.

Less than one hour

In 1916, an agreement was made with Knickerbocker Motors Co., Poughkeepsie, N.Y., to manufacture the tractor attachments and Walter resigned his position as production manager of Kelly-Springfield Motor Truck Co.

Knickerbocker Forma-Tractor attachments initially sold for $250 ($5,364 today), although a sticker attached to the 1917 sales folder I have shows the price to have been raised to $300, f.o.b. Poughkeepsie, N.Y. That price included a “water circulator” to enhance the Model T’s thermosiphon cooling system worth $7.50, a larger cooling fan worth $4 and an oversize “honeycomb radiator” that cost $60 if bought separately.

“Any layman can attach the Forma-Tractor to the Ford in less than one hour,” company promotional material claimed, “and remove it in 15 minutes without in any way marring the car.” One selling point for many of these conversion attachments was how easily they could be put on and removed, allowing farmers to do tractor fieldwork during the week and drive the car to town on Saturday and church on Sunday. Somehow, I doubt that it was that easy; the rear fenders and running boards had to be removed and then remounted — and those rear tractor wheels look heavy!

Meeting a need

Walter Guilder wrote: “My brother once said to me, ‘Why should a man already owning a Ford car pay $1,200 for a [tractor], when $250 will do?’” Knickerbocker Motors President Herbert Streat wrote: “For $250 for the Forma-Tractor plus $450 for the Ford touring car, a man can have a tractor and a pleasure car combined — ready for use when wanted.”

Based on “actual field reports,” the Knickerbocker Forma-Tractor was said to consume an average of less than 1-1/2 gallons of gas and 1/2 pint of oil per hour. When pulling two 12-inch bottoms, it could plow 6 acres in 10 hours, using about 15 gallons of gas and 2 quarts of oil. At 22 cents per gallon of gas and 15 cents per quart of oil, that would be a total of $3.60 per day. Add the driver’s wage of $2 per day and 40 cents for miscellaneous expenses, and total plowing expenses would be about $1 per acre ($21 today).

The brochure sums up the advantages of the Knickerbocker Forma-Tractor by stating: “It is the only machine guaranteed not only against defective material, but guaranteed to do the work on the farm.”

Clarke may have been right, but during the 1920s and ‘30s many, many Ford, Chevy, Dodge, and other cars and trucks were converted into more or less serviceable farm tractors. FC

Sam Moore grew up on a farm in western Pennsylvania. He now lives in Salem, Ohio, and collects antique tractors, implements and related items. Contact Sam by email at

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