CHICAGO — Daimler Trucks North America LLC is investing $120 million to expand production at its Detroit Diesel Corp. subsidiary’s headquarters in Redford, Mich.

Detroit Diesel expects to hire an additional 115 workers to make the Detroit DT12 automated manual transmission and the new asymmetric turbocharger Detroit DD15 at Redford, according to Daimler Trucks parent Daimler AG. The Redford plant currently manufactures powertrain aggregates for the Freightliner Trucks and Western Star Trucks brands.

With the expansion, Portland, Ore.-based Daimler Trucks said it will become the first commercial vehicle manufacturer in the North American Free Trade Agreement region to offer a fully integrated powertrain from its own production.

"Under the umbrella of our components brand Detroit Diesel, we combine engines, axles and transmissions into an efficient, fully integrated powertrain," Andreas Renschler, the Daimler AG board member who manages the Daimler Trucks and Daimler Buses divisions, said in a statement. "We will offer this powertrain portfolio in all our U.S.-built trucks in the future," he added.

With its localization strategy, Daimler Trucks can effectively optimize costs, production processes and quality with its cross-brand modular strategy and global production network, Renschler said, which will benefit customers in the end.

"A fully integrated powertrain from a single source is a decisive competitive advantage," Martin Daum, president and chief executive officer of Daimler Trucks, said in the statement. "That is why we decided in favor of the Redford location."

Daimler Trucks’ entire vehicle program in the 2013 model year, which includes long-distance and medium-duty trucks as well as construction and municipal trucks, is fully compliant with the U.S. Environmental Protection Agency’s GHG14 Standard, which aims to reduce greenhouse gas emissions for medium- and heavy-duty trucks by 2014.