Grand Cherokee L

Make
Jeep
Segment
SUV

"Going back to the drawing board" or "starting with a clean sheet design" can be both a good and a bad thing. It can be bad because you're starting over, throwing away all your previous work. However, if you're Chrysler, turned FCA, turned Stellantis and are building the umpteenth version of something, a clean sheet design allows you to use everything learned over the past 100 years or so. The multinational, global company dropped $1.6 billion into the complete redesign of the Detroit Assembly Complex - Mack, where it will be building the sure-to-be popular new three-row Jeep Grand Cherokee L. CarBuzz got a tour of the plant, before getting to drive the biggest Grand Cherokee yet.

Detroit Assembly Complex - Mack timeline

-1916: Michigan Stamping Company, the first automotive use for the Mack site

-1920: Briggs Manufacturing purchases plant

-1953: Chrysler Corporation purchases Briggs, acquires Mack property

-1975: Chrysler builds 1-million square foot expansion next to "Old Mack"

-1982-1989: Old Mack sits idled

-1995: Old Mack leveled, Viper production moves to Connor Avenue Assembly Plant

-1996: Construction of Mack Engine begins, opens in 1998 to produced V8s

-2000: Mack Engine II construction completed to produce V6s

-2012: Mack Engine II idled

-2019: $1.6 billion investment to create a space to build the three-row Grand Cherokee L

The new Mack Engine Complex, completed in just two years, is the first new Detroit manufacturing plant in three decades and has created thousands of jobs for local Detroit workers. It now consists of three buildings, body, assembly and paint, and the property covers more than 7 million square feet at the edge of Detroit proper. It has one line, currently working on the new three-row, but it will also house the two-row Grand Cherokee in both base and 4xe trims.

The plant runs 8-hour shifts, 3 shifts a day, 15 shifts a week with almost 5,000 workers. They're young workers too, with a plant average age of just 40 years old. And walking through the facility, the group looked it. We joked some of them could be in high school, though we know you need at least a high school degree to be employed there.

The place is huge, but since everything was created from scratch, it's easy to get around. The line called Trim 1 is next to the line called Trim 2, and then 3 and 4. Then it goes back to 1 for the next area. It doesn't seem crowded either, but we guess with millions of square feet, 1,300 employees don't take up too much space. The body shop alone has 578 robots doing the heavy lifting, while the paint shop counts 124.

This is isn't a turn-of-the-20th century, smokey, dirty, dangerous place to work. The floors are shiny and brightly lit. It smells, well it smells like a warehouse, with a little metal in the air from the welding. Flat-screen TVs tell you which line you're on and moving hi-los have bright blue lights and beeps to warn workers of their approach. Security is tight, as are Covid protocols, with almost everyone we saw completely masked up.

The biggest and most difficult change was the adjustment of the trusses. The bodies of the vehicles are above, and the chassis are below, on the same line. They eventually meet, but the building as it was constructed couldn't fit them both. So, engineers had to cut out the center portion of each truss individually and move each up 3 feet. And then reinforce them.

We checked out the near laser radar first with Greg Momotiuk. It was two big robot arms with cameras on the ends. Between them was the body of a Grand Cherokee L.

"We have two Nikon laser radar heads, and whatever it can see, it can measure. Everything from features on the car that the customer can see, to processing points that the body shop uses to complete car and points like suspension points that are meant for downstream," said Momotiuk. "There are about 800-900 points to measure; it takes about 45 minutes, and it can run all day and all night over three shifts."

After, we went to the part of the line that installs the attach points for the hood, fenders, doors and liftgates. "For our fenders, for the height, we try to set everything to perfect body lines. So, the doors fit and the fenders fit, it measures the vehicle, sets forms for the pads so everything fits nice and smooth and even," said Mike Licht, maintenance manager. "We also have a robot that loads the liftgate, finds the best position, and runs the bolts through. This is one of our higher tech lines."

Everything is pointed towards the health of the workers. The complete wiring harnesses are set in containers that are dropped off in the body. Later, workers jump in and spread the miles of wire in all the right places. Previously, those heavy harnesses were moved by humans.

General Assembly is probably the coolest part. That's where the engines join the chassis, and eventually meet the body.

"This is what a fully dressed chassis and powertrain looks like. Then it meets the body, which has been through five lines of trim," said Michael Brieda, plant manager. "In this area they'll start to synchronize with the overhead carrier. The operators at the four corners take over and lift the chassis into place."

The next part of the line was for the underbody secure points. There workers use their powered carts to get everything together. It's for ergonomics, to make sure "every worker goes home just like they came in," said Brieda.

Our final stop was the Buzz, Squeaks and Rattles department where Grand Cherokee Ls were taking loops on an indoor test track. It replicates the track they have outside, with a few added elements. It consists of wavy roads, train track simulators and other road nuisances. The BSR department also features a shaker that attaches to the wheels of a vehicle and replicates more jouncing, jiggling, rocking and twisting. It can replicate more events than the test track, Ray Peterson, product vehicle engineering lead, told us. We were surprised to see humans listening for said buzzes, squeaks and rattles, as opposed to a computer. But Peterson explained the reason. "Humans know exactly what to listen for."

And that really is the whole plant summed up. It's a ton of robots, a ton of computers, doing a ton of work. But none could operate independently of a human. They need to be programmed initially, watched closely, or used constantly to lift heavy stuff. The shorthand language used on those TV screens and placards for where you are in the plant, or the status the production, aren't for robots, they're for humans. And when you start with a clean sheet design, you can make those thousands of working humans happier, healthier and more productive.