John Deere 4020 Tractor HP, Price, Review, Specs, History, Serial Numbers, Weight, Features & Images The John Deere 4020 was an agricultural tractor model built by John Deere Manufacturing company from 1964 to 1972. John Deere 4020 replaced the nearly identical John Deere 4010 introduced with Deere's New Generation series in 1960 and offered several improvements over the … [Read more...] about John Deere 4020 HP, Price, Specs, Serial Numbers, History & Features