Simpson Jumbo

From 1947 to 1952, Jumbo Steel Products, located in Azusa, California, manufactured a series of tractors known as the Simpson. The design of these Simpson Jumbo tractors drew considerable inspiration from the Custom tractor originally built in Shelbyville, Indiana. It appears Jumbo Steel may have held a licensing agreement to build these tractors specifically for distribution throughout the western United States. Powering the Simpson Jumbo was a robust Chrysler industrial engine. In 1952, ownership of the Jumbo Steel facility transitioned to American Brake Shoe, ultimately bringing an end to tractor production – a cessation of manufacturing documented across varying sources to have occurred between 1949 and 1955.