Fordson Model F (1917–1928): How to Identify, Date and Check One
You've found an old steel-wheeled tractor with a worm-drive rear end and "Fordson" cast into it. Maybe it's at an auction, maybe it came with the farm, maybe a neighbor wants it gone. Before you can price it, order parts or try to start it, you need answers to three questions: is it a Model F or the later Model N, what year was it built, and what is likely to be wrong with it after a hundred years?
Those questions are harder than they look. Tractor Data counts 747,681 Model Fs built in the US and another 7,597 in Cork, Ireland (Tractor Data), and over a century plenty of them have picked up wheels, fenders and engine blocks from other tractors. This guide covers what to look at and in what order.
A short history
The Fordson was built by Henry Ford & Son, a company Ford set up separately from Ford Motor Company. Tractor Data notes that the "Ford Tractor" name was already taken by a Minneapolis company, which is part of why the tractor ended up called a Fordson. Production started in 1917, with an early batch going to a Britain that was short of food and horses during World War I.
The F had no frame. The engine, transmission case and rear axle housing bolted together and were the tractor, which cut weight and cost. In February 1922 Ford cut the price from $625 to $395, and the Fordson dominated the US market for several years (Wikipedia summary of the period). It also had a deadly habit: if the plow snagged, the worm drive kept turning and the front end could come up and over onto the driver. Early tractors had no brakes at all. Ford ended US production in early 1928, and the design moved to Cork as the Fordson Model N.
| Engine | 4-cylinder, 251 cu in (4 in bore x 5 in stroke) |
| Fuel | Started on gasoline, run on kerosene |
| Ignition | Low-tension magneto built into the flywheel, feeding Model T-style trembler coils |
| Transmission | 3 forward speeds, worm-gear final drive |
| Weight | About 2,920 lb (Tractor Data) |
| Nebraska tests | 1920 (Test 18): 19.15 belt hp, 9.34 drawbar hp. 1926 (Test 124): 22.28 belt hp, 12.33 drawbar hp |
| Built | About 755,000: 747,681 in the US (1917–1928) and 7,597 in Cork, Ireland (1919–1922) |
How to tell a Model F from a Model N
From ten feet away they look nearly identical: gray-ish, worm drive, no frame. These are the features that separate them.
- Serial number. The F sequence ends at 747,681. The Model N picks up at 747,682 (Tractor Data, Model N). If the block is original, this settles it.
- Ignition. The F has no separate magneto on the engine. Its low-tension magneto is built into the flywheel and feeds a box of trembler coils, the same idea as a Model T. The N uses a separate high-tension magneto (Tractor Data lists a Bosch unit).
- Fenders. Rear fenders were standard on the N (Grace's Guide). Fs had none until square-ended fenders appeared in 1923 (Gas Engine Magazine). So a tractor with no fenders and no mounting holes for them points to an F, but fenders alone don't prove an N.
- Bore. The F's bore is 4 inches, the N's is 4-1/8 inches. If the head is off, measure. It matters when you buy pistons.
Don't lean on paint. Gas Engine Magazine says the earliest tractors, built for the British government, sometimes show a dark green-gray with red wheels, and that the gray got lighter over the years. Cork-built Ns were gray too (Gas Engine Magazine). After a century, most of these have been repainted at least once.
Dating an F by its features
A few running changes help confirm what the serial number says. According to Gas Engine Magazine:
- 1918 tractors had six-spoke rear wheels, "ladder-side" radiator castings, and no fenders.
- Seven-spoke rear wheels didn't arrive until the end of 1919.
- Square-ended fenders and a reinforced dash arrived in 1923.
Wheels were swapped constantly, so treat these as supporting evidence, not proof.
Where the serial number is and how to read it
Tractor Data puts the Model F serial number below the cylinder head on the right side of the engine. Clean the area with a wire brush and solvent, then read it with a light held low and to one side so the stamping casts shadows. The number is a plain sequence with no model code. Compare it to the starting numbers for each year (US-built, from Tractor Data):
- 1917: 1
- 1918: 260
- 1919: 34,427
- 1920: 100,001
- 1921: 158,312
- 1922: 201,026
- 1923: 268,583
- 1924: 370,351
- 1925: 455,360
- 1926: 557,608
- 1927: 629,830 (US production ended at 747,681 in early 1928)
Worked example (made-up number): say the block reads 412,500. That's at or above the 1924 start (370,351) and below the 1925 start (455,360), so it's a 1924 US-built tractor. A 1924 tractor should have seven-spoke rear wheels, and fenders would be correct for it. If you find six-spoke wheels and ladder-side radiator castings instead, something has been swapped, possibly the block itself.
Two cautions. First, the Cork-built Fs of 1919–1922 used their own numbers (starting at 63,001 in 1919, 65,001 in 1920, 108,230 in 1921 and 109,673 in 1922, per Tractor Data), and those overlap the US sequence. A number in that range can't tell you on its own which side of the Atlantic the tractor came from. Second, the number is on the block, so it dates the engine, not necessarily the rest of the tractor.
What to check before you buy or try to start one
- Will it turn over? With the spark plugs out, try turning the engine slowly with the crank. If it won't move, stop. Forcing a seized engine can break rings or a piston.
- The ignition. No spark usually leads back to the coil box or the flywheel magneto. Check the coils first. They're the easier part to reach.
- The block. Look closely at the sides of the water jacket for freeze cracks and old brazed or epoxy repairs.
- The worm and wheel. Listen for a clunk as the drive takes up, and drain a little oil from the rear housing to look for metal flakes. A worn worm drive is costly to put right.
- Brakes. Find out what, if anything, stops this particular tractor. On an early one, the clutch may be the only thing that does.
Mistakes to avoid
- Hitching high. Never hitch to the axle or anything above the drawbar. That's exactly the setup that flipped Fordsons, and the worm drive still behaves the same way.
- Ordering pistons by name. "Fordson" pistons come in at least two bore sizes (4 in for the F, 4-1/8 in for the N). Measure first.
- Dating it by paint or fenders. Both get changed. Start with the serial number and use the features to check it.
- Grinding the serial pad. A flap disc can wipe out shallow stamping in seconds. Use a wire brush and solvent, and if the number is faint, rub chalk across it to bring it out.
- Running it hard on the first start. After decades of sitting, change the oil, flush the cooling system and check the rear housing oil before you put it to work.
If you're comparing early tractors, the John Deere Waterloo Boy is the Fordson's best-known competitor from the same years. And when Ford came back to US tractor building in 1939, it was with the very different Ford 9N.