To the casual observer, watching the all-new 2022 Jeep Grand Cherokee L roll off the Mack Avenue assembly line in Detroit is wholly unremarkable. It’s a new model being built at a refurbished assembly plant. But for Stellantis, and the city of Detroit, it’s a far bigger story.
If any plant symbolizes Detroit’s varying fortunes, it’s Mack Avenue, a site that’s been a key part of the automotive industry since the Michigan Stamping Co. was established here in 1916. Four years later, Briggs Manufacturing purchased the company.
Stamping bodies at its plants for Stutz, Hudson, Pierce-Arrow, Lincoln, and Ford, Packard and Chrysler becoming Briggs’ biggest customers, particularly after Briggs acquires custom coachbuilder LeBaron in 1927. In 1953, Chrysler acquired Briggs, including the Mack Avenue plant. Yet the complex closes in 1979, despite having a 1-million square-foot addition added in 1975 and dubbed New Mack. In 1982, the site is sold to the city of Detroit.
Filled with industrial toxins, the city is unable to resell it, and Old Mack remains idle through 1990, when the EPA demands that Old Mack plant be remediated. In 1995, it’s demolished after 11 million pounds of water, 10 million pounds of contaminated materials, and 16 million tons of debris are removed. The following year, construction begins on a new Mack Engine plant, which opens in 1998 to produce Chrysler’s new 4.7-liter V8 engine.
While this is happening, New Mack reopens to build the 1991-95 Dodge Viper before production moves to another former Briggs facility, the Conner Avenue Plant, in 1996. New Mack, now dubbed Mack II, is reconfigured to produce Pentastar V-6 engines, which it does from 2000 through 2012.
A new lease on life for Mack Avenue
In 2019, Fiat Chrysler Automobiles announces a $1.6 billion investment to convert the two plants into a future assembly site for the next-generation Jeep Grand Cherokee. The plans call for the construction of a new paint shop.
In all, the revival of the Mack Avenue Complex is the first new assembly plant in Detroit since Chrysler’s neighboring Jefferson North plant opened in 1992. In all, the revived facility’s 3 million square feet of factory floor space resides on 266 acres, consisting of three buildings: the body shop, the paint shop and general assembly.
Production of the Grand Cherokee L launches in March 2021 with three shifts per day, five days a week. While more experienced workers man the first shift, later shifts comprises new workers, many of whom have never worked in an assembly plant. But the new jobs are contributing to improving the area around the complex, where many of its workers live.
A very different workforce
The workforce at the Mack Avenue plant is considered young, according to Jeep. The average Mack Avenue employee is 40 years old and has worked for the company for five years. Ninety-two percent are blue collar with predominately a high-school education.
The remaining 8% are white collar. Overall, 64% of the facility’s workers are male, 36% female. In all, 4,900 people are employed at the site, with 3,850 being new positions filled by 2,100 local residents, most of whom have never worked in an assembly plant.
What they build
It takes 36 hours to produce the all-new 2022 Jeep Grand Cherokee L, known internally as the WL. The company hopes to produce 48 to 52 vehicles per hour once the plant is up to speed, at which point the next generation Jeep Grand Cherokee will be built there in the third quarter, as well as plug-in hybrid models at a later date. The 2021 Jeep Grand Cherokee is known as the WK, and is built at Jefferson North.
Mack Avenue’s manufacturing trifecta
Production starts in the former Mack II plant, now known as the Body Shop. With 650,000 square feet of space, the Grand Cherokee’s stampings, produced at the company’s Warren Stamping plant in Warren, Michigan, come together in a little more than two hours with the help of 578 robots.
Once completed, every Jeep body is subjected to a 45-minute validation test. From here, the bodies head next door to be painted in the Paint Shop, an all-new 800,000 square-foot facility that uses a fully automated six-step paint process that takes 12 hours and requires 124 robots before the bodies head to general assembly.
The final step is validation, where each vehicle’s automated driver assist systems are checked, headlights are aimed, and the body is subjected to a water leak test by 600 nozzles pummeling the Jeep with water at 30 psi for three minutes.
With 1 million square feet, the building once known as Mack I is where now used for general assembly, where each engine is dressed and married with the chassis, electrical connections are made, fluids are filled, glass, seats and trim installed and doors are hung.
Each Jeep also undergoes to a squeak and rattle test, where it is driven on an enclosed test track for three minutes. The 2,000-foot track simulates driving over potholes, manhole covers, rumble strips, cobblestones, speed bumps, gravel and other real-world conditions.
Finally, each Jeep is loaded onto one of the 76 trucks or 95 railcars that leave the factory daily.
For Jeep, Stellantis, and the city of Detroit, Mack Avenue and its history of manufacturing, corporate takeovers, abandonment, decay and revival is one that mirrors the city itself.