Daimler DT 12 Auto goes into production

Daimler Trucks new automatic transmission for the Cascadia has gone into production at the German company's Gaggenau plant, ready for use in Freightliner's Cascadia Evolution by mid-year.

To mark the occasion, a small group of North American journalists (me included) journeyed in April to the plant in the heart of Germany's Black Forest to see the commissioning of the production line that will initially supply the 12-speed automated transmission for the North American market. In 2015, production moves to the Detroit facility in Redford, Mich.

Daimler Trucks NA anticipates as much as 30% of Cascadia production will use the 12-speed automated transmission that, coupled to the latest generation of DD15 Detroit engine, offers fuel savings of 5% or more in the Cascadia Evolution. The single countershaft transmission also provides a 60kg (132 lb) weight savings over current competitive Eaton transmissions.

Quality processes

The Gaggenau factory machines and cuts gears and shafts, producing up to 150,000 transmissions annually for light, medium and heavy-duty Mercedes-Benz, Fuso and Freightliner products around the world. The DT 12, a new model for North America, shares the same internals with the automated transmission that was introduced with the cabover Mercedes New Actros, which was introduced two years ago. Thus it’s been in well-proven applications for two years.

Changes for the North American version consist of converting from Europe's 24V truck electrical system to North America's 12V. Software changes allow for communication with the American SAE/TMC chassis electrical architecture instead of the European CanBus.

New Actros, as the highly sophisticate new European cabover is called, was introduced with the OM471 and 472 engines, which are all but identical to the DD13 and 15 engines. This marks the first outside-America application of Daimler's worldwide Heavy Duty Engine Platform, which will also power Fuso trucks from Japan.

North America was the first to see these engines introduced in 2006, so where Freightliner will benefit from the Mercedes-proven automated transmission, Mercedes-Benz benefits from new engines already proven in N.A. markets. Both brands also benefit from the integration of engine and transmission, says Daimler, with the deeper communication made possible by proprietary components, electronic controls and software for greater optimization and a richer feature set than is possible with either a supplier engine or transmission.

Worth the trip

At the factory, we saw how gears are manufactured with tolerances as tight as a half micron for reliability and durability, as well as less noise in operation. The transmissions are warrantied for 750,000 miles, showing Daimler's confidence in its design and production processes. Much of the machining is done on fully automated lines with the plant running at close to 2,000 units per day. Transmissions are assembled at the neighboring Rastatt plant.

Gaggenau is, incidentally, the oldest vehicle and component production facility in the world. Commissioned in 1894, it became the site where Carl Benz produced his early cars in 1907.

Later, we went to the Worth truck plant about an hour away to see Mercedes-Benz trucks being built with Gaggenau transmissions and the inline 6-cylinder HDEP engines, sourced from the engine plant in Mannheim, Germany. Another historical note: Mannheim was also a Benz factory, while Gottlieb Daimler's production was in Stuttgart. In 1926 the two producers combined into Daimler-Benz.

The new Actros is assembled at Worth beside heritage models of the Actros that still use the V6 and V8 diesels and other A-line trucks that include the newly introduced Arocs heavy vocational chassis, the regional Antos and Axor, and the lighter Atego. Worth also produces specialized vehicles for unique markets.