Chrysler Mack Avenue plant

The Chrysler Mack Avenue plant, located at 4000 St. Jean Avenue in Detroit, Michigan, has been a significant site in the American automotive industry for over a century, evolving from a producer of car bodies to a major engine manufacturing facility and, since 2021, an assembly plant for the Jeep Grand Cherokee. The plant's history reflects the changing fortunes of the auto industry in Detroit and the broader economic shifts affecting the region. Its continued operation, following a $1.6 billion investment and large-scale redevelopment completed in 2021, shows a firm commitment to manufacturing within the city limits.

History

The site's origins trace back to 1916, when it was first occupied by the Michigan Stamping Company, which produced metal stampings for the emerging automotive trade. In 1920, the Briggs Manufacturing Company acquired the property and began producing complete automotive bodies for major manufacturers including Ford and Plymouth. By the 1930s, Briggs had grown into one of the largest independent auto body suppliers in the United States, and the Mack Avenue plant was a central part of its operations. The plant remained under Briggs' ownership for over three decades, supplying bodies through the Depression era and the wartime production years of the early 1940s, when Detroit's auto factories were broadly retooled to support military manufacturing.

In 1953, Chrysler Corporation acquired the Mack Avenue plant as part of a broader purchase of Briggs Manufacturing Company, one of the most significant supplier consolidations of the postwar era. Chrysler gained control of the land, buildings, and ongoing body production operations, and subsequently redirected the plant toward stamping parts to support the nearby Dodge Main assembly complex. Stamping operations continued through subsequent decades as Detroit's automotive manufacturing footprint expanded and then, in later years, began to contract around it.

From 1991 to 1995, a newer section of the facility, sometimes referred to informally as the "New Mack" plant, was used for limited-volume assembly of the Dodge Viper, before that production line was relocated to the Conner Avenue Assembly Plant, which itself closed in 2010. The Viper's presence at Mack was always an anomaly, a low-volume sports car assembled on a site historically built around mass production. In 1995, the older sections of the Mack plant were demolished and the entire site underwent environmental remediation to address decades of industrial contamination before new construction could begin.

A new facility built on the remediated site opened in 1998 as the Mack Avenue Engine Plant. Over the following fourteen years, the plant produced nearly three million engines, including the PowerTech and HEMI V8 engine families that powered a wide range of Chrysler, Dodge, and Jeep vehicles. That run ended in 2012, when the plant was idled as Chrysler, which had passed through the DaimlerChrysler era and a 2009 bankruptcy before re-emerging under Fiat Chrysler Automobiles (FCA), evaluated the site's future role. Three years of corporate restructuring had reshaped priorities across the company's manufacturing network, and Mack sat unused while those decisions played out.

In January 2019, FCA announced a $1.6 billion investment to convert the Mack Avenue site, along with the nearby Jefferson North Assembly Plant, into the Detroit Assembly Complex, a move the company described as its largest investment in Detroit in decades. The plan called for the Mack site, designated Detroit Assembly Complex - Mack (DAC - Mack), to assemble the next-generation Jeep Grand Cherokee, including plug-in hybrid variants. Construction and retooling work proceeded through 2020 and into 2021. Production of the fifth-generation Jeep Grand Cherokee began at the plant in 2021, with the facility also responsible for building the three-row Jeep Grand Cherokee L and the Jeep Grand Cherokee 4xe plug-in hybrid. FCA merged with PSA Group to form Stellantis in January 2021, and the plant has operated under that corporate name since.

In early 2025, Stellantis confirmed plans to shift production of the Dodge Durango to the Detroit Assembly Complex, consolidating more of its Michigan manufacturing operations at the site.

Geography

The Chrysler Mack Avenue plant occupies a 178-acre site at 4000 St. Jean Avenue in Detroit, at coordinates 42°23′03″N 82°58′44″W. The facility encompasses approximately 2,500,000 square feet of manufacturing space spread across the redeveloped site. That scale places it among the larger auto assembly sites in Michigan. The location provides access to major transportation routes, including proximity to Interstate 96, which supports the movement of parts and finished vehicles across the region.

The surrounding area is a mix of industrial and residential land use, characteristic of Detroit's east side neighborhoods. The plant sits within the broader MotorCities National Heritage Area, which recognizes the region's role in the development of the American automobile industry. The 2019 to 2021 redevelopment involved substantial new construction and infrastructure upgrades to accommodate modern assembly operations, including body shop, paint shop, and general assembly buildings designed around the Grand Cherokee platform. The physical character of the site has changed substantially since its stamping-plant origins, but its footprint and general location in Detroit's industrial corridor remain consistent with more than a century of continuous manufacturing use.

Economy

The plant has been a consistent source of employment in Detroit across its various operating phases. As of 2022, the Detroit Assembly Complex - Mack employs approximately 4,103 workers, in roles ranging from skilled trades to production and managerial positions. Those jobs ripple outward into the regional supply chain, touching parts suppliers, logistics firms, and service businesses that depend on the plant's output.

The $1.6 billion investment announced in 2019 was the centerpiece of a broader FCA commitment totaling $4.5 billion in Michigan manufacturing, with the expectation of creating or retaining thousands of jobs across the state. For Detroit specifically, the Mack Avenue conversion carried symbolic weight beyond its dollar figure. The city had seen numerous auto plants close or downsize in the preceding two decades, and a greenfield-style rebuild on a long-idled industrial site was a notable reversal of that trend. The plant contributes to local property and income tax revenues and has been cited by city officials as part of a broader effort to stabilize Detroit's manufacturing employment base.

Not without complications. In late 2024 and early 2025, vehicles stored in holding lots near the Detroit Assembly Complex were targeted in a series of thefts, with thieves driving off in new Jeep and Ram vehicles from staging areas near the plant. The incidents drew attention to security vulnerabilities at finished-vehicle staging lots and prompted responses from both Stellantis and local law enforcement. Stellantis subsequently deployed additional security measures at its Detroit facilities, including trained security dogs, in response to the incidents. Workers at the plant also raised concerns about internal safety and complaint processes during this period, with employees indicating that grievances received more attention following public scrutiny of conditions at the facility.

Access

The plant is accessible primarily via St. Jean Avenue, which runs directly to the facility entrance. Interstate 96 is the nearest freeway connection, linking the site to the broader Detroit metro highway network. Detroit Department of Transportation (DDOT) bus routes serve the surrounding area, providing transit access for employees who don't drive to the site.

Employee parking is available on-site. The plant's east-side location puts it within reasonable distance of several Detroit neighborhoods as well as the nearby city of Grosse Pointe Park, though road congestion during shift changes can affect travel times on local streets. Carpooling and ride-share services are commonly used by the workforce given the plant's size and shift structure.