The John Deere GP was a general purpose row crop tractor that was produced from 1928 to 1935. It was originally called the Model C, but there was a lot of confusion between it and the Model D. Since International was having success with the Farmall, John Deere decided just to call it the GP in order to better their chances of competing. The GP had a fixed front axle that straddled three rows. It also had two 14-inch plows, and weighed 3,600 pounds.
John Deere’s GP was a two-wheel drive tractor with manual steering. It had a two-cylinder kerosene engine that was liquid-cooled. The original GPs had a bore and stroke of 5.75×6 inches, a displacement of 311.6 ci, and 900 rated RPMs. In 1931, the engine was improved a bit. A water-injection system prevented a knocking sound that came with the use of low-quality kerosene. It now had a bore and stroke of 6×6 inches, a displacement of 339.3 ci, and 950 rated RPMs.
The GP used a three-speed unsynchronized gear transmission that had one reverse speed. The top speed in third gear was 4.1mph. With the original engine, the GP had a maximum belt power of 24.97hp, maximum drawbar power of 17.24hp, maximum drawbar pull of 2,489 pounds, and maximum belt fuel use of 3.5gallons an hour. Once the engine was improved, the maximum belt power was 25.36hp, the maximum drawbar power was 18.86hp, the maximum drawbar pull was 2,853 pounds, and the maximum belt fuel use was 3.4 gallons an hour.
While the GP was the most popular and most manufactured, there were other versions. The GPWT had a wider tread. The rear axle was 76 inches across, and the tractor had a tricycle-style front tire. The GP-P, created specifically for use in potato fields, was similar in style to the GPWT but had a 68inch rear axle. The GPO was created for orchard-use. It was lowered and had fenders.
The serial number for the John Deere GP is located under the gear shifter. Production year corresponds with the serial number as follows:
GP:
1928: 200211-201335
1929: 201336-212037
1930: 212038-223802
1931: 223803-228665
1932: 228666-229050
1933: 229051-229215
1934: 229216-230513
1935: 230514-230745
GPWT:
1929: 400000-400935
1930: 400936-402740
John Deere GP Tractors & Parts For Sale
Comments On The John Deere GP
Leave Your Comments On The John Deere GP
zerodtkjoe on 10.20.2010
Thanks for the info!
Craig on 01.16.2016
Hello, my brother bought my grandparents house a few years back and I’ve been helping him clean the property up since then. Underneath all this brush I found a front axle for an early John Deere GP front axle. This part # is C1878R. I’m writing this because I’d like to know how much this part is worth? Thanks
Eli on 10.01.2017
Can anyone tell me what the casting numbers on a 31 GP cylinder head is,thanks
Angela Key on 03.29.2018
I have a hood off of an old john deere tractor. I was told it was from around 1928-1929. Do you have any idea as to the value?