Diamond T Trucks: The Diamond T company built cars in Chicago from 1905 to 1911 and then started making trucks using components from other companies. During World War II they built trucks for the U.S. Army and afterwards they sold out to the White Motor Company. White then combined Diamond T with their REO line of trucks to form Diamond Reo Trucks in 1967. This category is open to any and all types of Diamond T trucks and equipment. You will also find related products and services in our Business Directory.