The two tractors were behind a fence and the museum was not yet open for the summer when we visited, so we couldn't go around the back to check tor a serial number. A post "Spoker", or solid flywheel model, this "D" was built after 1925, but likely before 1935, likely right around 1930. It's in pretty poor condition, with rust having eaten clean through the fuel tank. Notice the extensions on the rear wheels - this tractor was likely used on soft ground.
The "D" used a 465 c.i. engine until 1927, when the displacement was upped to 501 c.i. - pretty big for a two cylinder engine. Tested horsepower at the belt 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 nearly 200,000 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.
Tractor Information:
The D had the longest run of any model of John Deere tractor, the styled and unstyled versions ran from March 1, 1923 until July 3, 1953. Serial numbers 31321 through 31412 are not model Ds, but are Waterloo Boy Ns which were built after model D production had begun.
From Tractor Data