While Cockshutt had an extensive line of tillage equipment and of harvest equipment, Cockshutt lacked a tractor to fill out is line up of farm machinery. With other machinery companies offering a complete line of machinery, Cockshutt was at a disadvantage. Farmers had a reason to visit another farm machinery dealer and while there the farmer could be “converted” to another make of machinery. Cockshutt noticed that its sales were slowly declining with farmers turning to other farm machinery companies. However Cockshutt also realized:

• that a large amount of money was needed to develop a tractor and tool up for production of this tractor,
• many companies building tractors had often  experienced a succession of troublesome tractor models,
• the Canadian market was relatively small and may not support a Canadian Company particularly when many US companies were active selling tractors into the Canadian market.

To fill out the line with a tractor, in 1928 Cockshutt began selling Allis Chalmers 20-35 tractor. In 1929 the Allis Chalmers Model U began to be sold by Cockshutt. However the Model U was plagued by engine problems which were severe enough that Allis Chalmers arranged for a short block engine exchange beginning in 1931. A new engine was introduced into the Model U in 1934.Cockshutt is suspected of being unhappy with the engine problems experienced by the Allis Chalmers tractors. Cockshutt signed an agreement in 1935 with the Oliver Company to market the Hart Parr line of tractors in Canada. Oliver had more production capacity than sales for Hart Parr tractors and so Oliver was interested in a larger share of Canadian tractor sales. And Cockshutt needed a good tractor line and the Canadian farmers were aware of the Hart Parr line of tractors.The first Hart Parr tractors sold by Cockshutt had the name Cockshutt cast into the radiator tank with the words Hart Parr in smaller letters cast below. The tractors came painted in a dark green with red wheels. Cockshutt sold the Model 60, 70 and 80 tractors produced by Oliver.The Oliver Model 8 tractor appeared in 1937 and stayed in production until 1948. The 80 was available in both standard tread and row crop configuration.  A Buda-Lanova diesel engine was an option that could be ordered on the Oliver 80. However the most common engine in an Oliver 80 was an internal combustion engine built by Waukesha for Oliver. This engine could either be set up for kerosene or gasoline fuel operation.