Allis-Chalmers DD grader of the 1950s. In the 1940s, Allis-Chalmers launched a new grader called the model 'D' to replace the former model 'W' tractor-mounted type at the lower end of its motor-grader ...

The Allis-Chalmers WD tractor was produced from 1948 to 1953 when it was replaced by the WD45 model with more power. However the WD45 retained the three unique features introduced by the WD.