This Cat RD4 Dozer, affectionately named Old Reliable was ... Introduced in 1936, the Caterpillar RD4 was a landmark diesel-powered, 10,000-pound crawler tractor that followed the successful gas-powered CAT 30. It used a 4-cylinder D4400 engine with a gasoline starting motor, quickly becoming essential for agriculture and construction. The RD4 was renamed the D4 in 1937, marking a shift toward modern diesel equipment. Does not have pony motor. Needs Restoration has original motor vin and matching body vin original. Asking 2500 OBO