LOUISVILLE, KY -- Daimler Trucks North America said its Detroit Transmission, a previously disclosed 12-speed automated mechanical unit based on a Mercedes-Benz design, initially will be available next year in Freightliner Cascadia tractors with Detroit diesels.
Detroit automated mechanical transmission will initially be available with Detroit engines in Freightliner's Cascadia road tractor.
Detroit automated mechanical transmission will initially be available with Detroit engines in Freightliner's Cascadia road tractor.
Later, it will also be available in Western Stars.

The new-to-North-America automated gearbox will complete an all-Detroit powertrain that will provide operational efficiencies for customers running over-the-road trucks, executives said. The third element comprises recently introduced Detroit axles.

"The Detroit integrated powertrain provides what no other manufacturer in North America can provide - a total product offering paired with the engineering expertise and global resources available only through a company like Daimler," said Andreas Renschler, head of Daimler Trucks and member of the Board of Management of Daimler AG, during the announcement at the Mid-America Trucking Show.

"Through our total vehicle integration approach, we are providing our customers with world-class technology that will result in the most powerful and fuel-efficient vehicles on the road today."

The development of Detroit's powertrain products has been an international effort, with resources being drawn from all of Daimler's global capabilities, he said. Daimler's transmission designs have been extensively tested and proven in series production in select European markets since 2005.

The Detroit AMT has an aluminum case and is a single-countershaft design that weighs about 300 pounds less than a dual-countershaft Eaton UltraShift Plus with a cast iron case, according to Mark Lambert, vice president of sales for Daimler Trucks North America.

The Detroit product might cost about $200 more than the Eaton, but will deliver superior performance, he said.

Freightliner will continue to offer Eaton AMTs with Detroit and Cummins engines, he said. By next year, DTNA will have three Class 8 automated mechanical transmissions on its options list, as well as fully automatic Allisons and its own medium-duty AMT. Eaton manual transmissions will continue to be standard in all trucks.

The Detroit AMT will be available with with direct- or overdrive top gears. It combines a traditional clutch-actuated manual gearbox with high-speed, computer-controlled shift and clutch actuators, which automatically and smoothly select the right shift sequence for good fuel economy and performance.

The direct-drive version will be Daimler's best technical solution to maximize fuel efficiency for line-haul and long haul operations, executives said. It combines improved slow-speed maneuvering with high road speed efficiency.

Features include active driveline protection, which anticipates torque windup, torque limiting to protect components at low speeds; a hill-start aid to keep the vehicle from rolling backward while stopped on an upgrade; and a kick-down function for brisk acceleration.

The Detroit Transmission uses skip shifting, enabling drivers to run through lower gears faster to achieve cruising speed sooner; and EcoRoll, which disengages the clutch on downgrades and certain other circumstances so the vehicle freewheels while coasting to further save fuel. The clutch re-engages when appropriate to ensure safe speed control.

The two-pedal product has helical gears that reduce noise; a control module that communicates with the entire powertrain; and a kick-down feature that improves vehicle acceleration.

It is easy to drive and improves mile-per-gallon performance for even novice drivers, Daimler executives said.