The John Deere Model D was built for 30 years, from 1923 to 1953, so "a Model D" can mean anything from a rare early spoker to a common late styled tractor. The value, the parts it takes, and how it should be restored all depend on which one it is. If you've inherited one, found one in a barn, or are looking at one at an auction, the question is the same: when was it built, and is it what the seller says it is?

This page walks through the three main eras (spoker, unstyled and styled), the features that identify each, where the serial number is on each and how to read it, and what to check on a survivor.

The D in brief

The D was the first tractor sold under the John Deere name in volume. It was developed at Waterloo after Deere bought the Waterloo Boy company in 1918, a deal that included Waterloo's experimental tractor designs. Like the Waterloo Boy, it has a horizontal two-cylinder engine, but it's a much more compact standard-tread tractor built for plowing and belt work rather than cultivating row crops. It ran on kerosene or distillate as well as gasoline. Tractor Data gives its run as March 1, 1923, to July 3, 1953, the longest of any John Deere model (Tractor Data). John Deere's diesel Model R arrived in 1949 as the next big standard-tread tractor, and the D was built alongside it until 1953.

Specifications

EngineHorizontal 2-cylinder: 465 cu in (6.5 x 7 in) to 1927, then 501 cu in (6.75 x 7 in)
FuelKerosene, distillate or gasoline
PowerAbout 30 belt hp and 22 drawbar hp in its 1924 Nebraska test; about 42 belt hp and 30 drawbar hp with the 501 engine in 1935
Transmission2-speed, 3-speed from 1935
BuiltWaterloo, Iowa, 1923–1953

Figures are from Tractor Data's engine, transmission and Nebraska test (tests 102 and 236) listings.

Spoker, unstyled or styled: identifying features

Spoker D (1923 to December 1925). The flywheel on the left side has spokes like a wagon wheel. The earliest tractors had a 26-inch spoked flywheel, which was reduced to 24 inches after it was found to strike the front wheel. The first spokers also had a fabricated (built-up, not cast) front axle (Green Magazine). Spokers are the most valuable Ds.

Unstyled D (December 1925 to 1938). The flywheel is solid. The first solid flywheels, starting at serial 36249 in December 1925, are the "nickel hole" flywheels, named for the small 7/8-inch holes at the ends of their stress slots. They cracked, and in March 1926 Deere lengthened the slots and enlarged the holes to two inches. Fewer than 2,500 tractors had the nickel-hole version, according to Green Magazine. There's no grille shell: the radiator is exposed at the front. Through the unstyled years, the 501 cu in engine arrived in 1927, a splined crankshaft and flywheel replaced the keyed design in 1928, and the three-speed transmission came in 1935.

Styled D (1939 to 1953). John Deere's lineup was restyled in 1939 by industrial designer Henry Dreyfuss. On the D this brought an enclosed grille and hood. Styled Ds have the 501 engine and three-speed transmission.

Finding and reading the serial number

The plate moved when the styling changed. Tractor Data gives:

  • Spoker and unstyled D: a serial number plate on the operator's platform, ahead of the seat mount.
  • Styled D: on the rear of the transmission case, below the shifter.

Clean a plate gently. Don't wire-wheel it.

Tractor Data's starting numbers for the unstyled D are model years, not build years:

  • 1924: 30401. 1925: 31280. 1926: 35309. 1927: 43410. 1928: 53388. 1929: 71645. 1930: 95367. 1931: 109944. 1932: 115509. 1933: 115665. 1934: 116273. 1935: 119100. 1936: 125079. 1937: 130700. 1938: 138413. 1939: 142300. Final unstyled: 143799.

The styled D starts at 143800 in 1939 and runs to 191670 in 1953. Its year starts are 1940: 146500, 1941: 148872, 1942: 151887, 1943: 154470, 1944: 155029, 1945: 158454, 1946: 161701, 1947: 164897, 1948: 171956, 1949: 180812, 1950: 187703, 1951: 189600, 1952: 190961 and 1953: 191405.

Worked example 1 (made-up number): a D with plate number 36100. That's below 36249, the first nickel-hole flywheel, so it should be a spoker. In Tractor Data's model-year list it falls after the 1926 start (35309), so it's a 1926 model-year tractor even though it was built before December 1925. If it has a solid flywheel, the flywheel has been replaced at some point.

Worked example 2 (made-up number): a styled D numbered 150000 falls between the 1941 start (148872) and the 1942 start (151887), so it's a 1941.

One trap: Tractor Data notes that serials 31321 through 31412 are not Ds at all but Waterloo Boy Ns built after D production began.

Inspecting a survivor or an auction tractor

  • Match the plate to the features. A spoker serial should have a spoked flywheel and early details. A styled serial should have the styled sheet metal and the plate on the transmission case. Mismatches mean replaced parts, which affect value.
  • The flywheel. Check every spoke and the area around the hub and stress slots for cracks, especially on a nickel-hole flywheel. On a spoker, look for welded spokes.
  • The crankshaft. A cracked or loose flywheel can damage the crankshaft. On a keyed-crank tractor (before 1928), check that the flywheel is tight on its key.
  • The engine. With the ignition off, roll it over by the flywheel and feel for compression on both cylinders. Look for freeze cracks in the block and cylinder heads.
  • Clutch and belt pulley. Check that the clutch engages and releases, and that the belt pulley turns true.

Mistakes to avoid

  • Calling it a spoker because of the flywheel. Flywheels get swapped. The serial number has to agree.
  • Reading a model-year table as a build date. An unstyled D's model year can be later than the date it left the factory.
  • Hand-starting it carelessly. Many Ds are started by rolling the flywheel by hand. Keep your thumb on the same side as your fingers, never wrap the rim, and stand clear of a kickback.
  • Running a cracked flywheel. A flywheel that comes apart at speed is dangerous. Replace it or have it properly assessed before running the tractor.
  • Restoring to the wrong era. Unstyled and styled sheet metal, flywheels and plates differ. Restore to the features the serial number calls for.

Two-cylinder parts are well supported by specialist suppliers and clubs. If your D has the original two-speed gearbox, how an unsynchronized transmission works explains how to shift it without grinding. For a 1920s rival, see the Fordson Model F.