Top 10 of 17 — Paccar’s 12-speed automated transmission
Posted: December 19, 2017 by John G. Smith
Paccar updated its MX-11 and MX-13 engines this year, shedding weight and extending oil drains in the process. But it was the company’s automated transmission – developed through the new Eaton-Cummins Automated Transmission Technologies – that garnered the most attention during recent product launches.
The 12-speed, twin-countershaft design is unlike other Automated Manual Transmissions (AMTs) because it was conceived as an automated model out of the gate. It isn’t a manual box fitted with add-on shift actuators. One of the benefits here is that it weighs 658 pounds, which is about 200 pounds lighter than an Eaton Advantage AMT, the company says.
The model supports linehaul applications with Gross Vehicle Weights of up to 110,000 pounds, and engines delivering up to 510 horsepower and 1,850 lb-ft of torque. The first units to roll off the assembly line are options with MX-13 engines.
The stalk-mounted controller is pretty elegant in its own right. A simple twist of the DNR selector makes it easy to shift between Drive and Reverse, while the Neutral position includes an interlock with the parking brake – so the transmission automatically shifts to neutral if the parking brakes are set when the shifter is in D or R. A button on the end of the controller transforms the unit into a paddle shifter for manual shifts.
Current buying habits suggest there will be a high take rate. More than 70% of today’s Kenworth T680 trucks, for example, already come with AMTs.