The Dual Range is a 4-speed automatic, and yes, it shifts hard. Instead of a torque converter it has a fluid coupling, which transmits torque, but does not multiply it when gertting moving from a dead stop. On the upside, there is almost no RPM loss through the coupling, instead of the 10% slip that's built into all torque converters.
Throttle valve pressure is critical to good shifting on a hydramatic. It's controlled by the linkage from the carburetor to the transmission. Adjusting the length a tiny bit will make major differences in shift points, and it can go from a slip to a slam-bang shift with little room for error.
Jerry
