The 4020 was an agricultural tractor model made by John Deere from 1964 to 1972. Between 1963 and 1972, over 184,000 tractors were sold, selling for about $10,345 each. It replaced the nearly identical 4010 that had been introduced with Deere's New Generation series in 1960 and offered a number of improvements over the previous model including more horsepower, heavier rear axles, and a differential lock