Tractor Trendsetters: Minneapolis-Moline M-504 and G-704
Written by Larry Gay
The Minneapolis-Moline Power Implement Company was formed in April 1929 by merging the former Moline Plow Company, the Minneapolis Threshing Company, and the Minneapolis Steel and Machinery Company. MS&M’s line of Twin City tractors were retained as MM models. In the late 1930s, Minneapolis-Moline introduced the R, Z, U, and G models with a styled hood and the Prairie Gold and red colors. The models evolved and for the 1962 model year, MM introduced the M-504 and G-704 with a factory-installed front-wheel assist. The front-wheel assist made the M-504 and G-704 tractor trendsetters.
Front-wheel assist first appeared as add-on kits in the late 1950s. Elencol Products of Aurora, Illinois, built front-wheel assist kits for several models of Ford tractors. Elwood Manufacturing Company of Elwood, Illinois, sold the EmCo brand of kits for selected models of International Harvester, John Deere, Massey-Ferguson, Minneapolis-Moline, and Case tractors.
When Minneapolis-Moline equipped its tractors with front-wheel assist, the 5-plow M-5 model became the M-504 and the large standard-tread G-VI became the G-704. The M-5 and G-VI were replaced by the M-602 and G-705 for 1963 and the front-wheel-assist versions became the M-604 and G-706. Oliver started offering factory-installed front-wheel assist for its 1800 and 1900 models for the 1963 model year. The other tractor brands added a front-wheel assist for some of their models during the 1960s.
During the 1970s, there was a big debate about whether the advantages of a front-wheel assist justified the added cost. Sales of U.S.-built tractors with front-wheel assist were limited, but many of the tractors imported from Europe and Japan were equipped with front-wheel assist. Some people thought dual rear wheels were a better way to improve traction. Others suggested buying a tractor with an extra 20 horsepower was a better way to compensate for wheel slip. The Nebraska Tractor Tests showed no extra drawbar pull for the front-wheel assist. However, the concrete test track did not duplicate field conditions and the tractor’s ballast was located to provide optimum performance with 2-wheel drive and was not relocated when the front-wheel assist was engaged.
Front-wheel assist first became a popular feature for utility tractors with loaders working in muddy conditions. By the 1980s, tractor engineers and most farmers agreed there was more drawbar pull and better fuel efficiency when the tractor was equipped with a front-wheel assist. Soon front-wheel assist became standard equipment on most tractors with 200 or more horsepower. Today most tractors of all sizes are equipped with front-wheel assist.
Larry Gay is the author of four tractor books and the "Machinery Milestones" articles in Heritage Iron magazine. To learn more about this magazine which focuses on the 1960-1985 era, go to heritageiron.com or call 1-855-old iron.