The Model D is the tractor pretty much everyone thinks of when they contemplate old John Deere tractors. It has the pop-pop-pop-pop sound old tractor lovers have learned to identify from miles away. There were not a lot of farmers who, if they didn't own one themselves, didn't have a neighbour who did. A post "Spoker", or solid flywheel model, this particular example bears serial number 56308, built in 1928. It seems that throughout the 30 year production run the power rating remained the same - Drawbar claimed horsepower: 15 - Belt claimed horsepower: 27.
Launched March 14, 1923, the "D" used a 465 c.i. engine from 1924 until 1939, when the displacement was upped to 501 c.i. - pretty big for a two cylinder engine. Tested horsepower was just over 41 at the belt and 30 at the drawbar, both substantially more than John Deere claimed. The transmission, until 1935, was a two speed, giving a top speed of 3.3 MPH in high gear at the rated engine speed of 800 RPM.
The "D" was produced over a span of 30 years, and enjoyed a production run longer than any other of John Deere's tractors. Of the 160,000 units sold, 47,870 were the "Styled" Ds, production of which began on April 7, 1939 and ended with the last John Deere D rolling off the line on March 19, 1954. The final D shipped in April of 1954. Though the factory shut down the assembly line for the Model D early in 1953, 92 more were produced outside on an ad hoc assembly line set up on the street behind the plant. Serial numbers 31321 through 31412 are not model Ds, but are Waterloo Boy Ns which were built after model D production had begun.