1. home
  2. how to
  3. body chassis
  4. General Motors Janesville Assembly Plant - The General's Assembly

General Motors Janesville Assembly Plant - The General's Assembly

Building fullsize GM SUVs in Janesville, Wisconsin

Ken BrubakerPhotographer, Writer

If you want to experience a true engineering marvel, visit a modern automobile assembly line. We did, and we'll say without reservation that you'll be astonished at the vast amount of technology, quality, and precise planning that goes into assembling a vehicle.

We recently toured the General Motors Janesville Assembly Plant in Janesville, Wisconsin. Janesville is one of the final assembly plants that produce all trim levels of the new, hot-selling Chevy Tahoe, Chevy Suburban, and the GMC Yukon and Yukon XL. The GM team granted us unrestricted access to the entire assembly line from start to finish so we could give you a virtual tour of how these exceptional SUVs are assembled.

It's important to remember that long before the complicated procedure of assembling (or "marrying," as they call it) the many components, GM invested a mind-boggling amount of time and money into an infrastructure that includes creative design engineers, quality suppliers, a just-in-time parts delivery system, cutting-edge robotics, and of course, a vast number of highly skilled employees.

After all that, one may think that the actual assembly process of these SUVs would be the easy part, but that is not true. The GMT900 SUVs are renowned for their tight and reliable build quality. To accomplish this, a vast amount of technology and quality control are integrated into the assembly process. As a matter of fact, we were left speechless after witnessing the attention to detail and tight quality control exhibited by the team at the Janesville plant. Add to this their focused priority on safety and the never-ending requirement of controlling costs, and it becomes apparent that these folks have their ducks (OK, trucks) in a row.

We'd love to show you how every component in the finely choreographed assembly procedure comes together because almost every step is fascinating and notable in its own right, but that would take hundreds of pages. Instead, follow along as we spotlight some of the highlights of this captivating and awe-inspiring procedure.

13. Here, the author and Durant check out a painted GMT 900 body. This area, called the strip bank, is a holding area of sorts. This area is used to store the painted bodies overnight when the line is not operating. We're wearing a variety of mandatory protective clothing designed to ensure that the paint area remains dirt- and dust-free.

14. This is the finesse area. Here the body is given an inspection to ensure that no dust or dirt has adhered to the body. If foreign material is found, it can be sanded and polished out. From this point the body continues on to the Hard Trim area. This is where things get even more complicated. Once the body is released from the body shop, a sequencing procedure is placed in motion behind the scenes that ensures that the various components of the vehicle are ordered and delivered to correspond exactly with the final assembly of that specific vehicle. In other words, there are several assembly lines working at the same time, and they all must be timed to deliver their product to final assembly at the correct moment. For instance, dashboards are being built, seats are being ordered and the frame, suspension, and powertrain are being built (we'll get to chassis assembly in a minute).

15. General Assembly Area Manager Gary West, a 27-year veteran of GM, took us through the rest of the process. This is the Hard Trim area, and this is where the doors and liftgate are removed from the vehicle so they can be sent to another line to be "built." Items installed in the Hard Trim area include the sunroof, roof rail, airbags, interior moldings, third seat, and instrument panel (which come from an in-house instrument panel assembly line). Here you can see a worker guiding a sunroof assembly through the windshield opening of a body. Interesting fact: There are hundreds of fasteners installed in the final assembly process. Computers monitor the torque pressure of each fastener as it's installed to ensure it is tightened to spec. If a fastener isn't correctly torqued, the assembly line stops until the proper torque is achieved. This guarantees a 100 percent perfect torque rate of all fasteners.

16. Here you can see a worker installing an overhead DVD system in the Soft Trim area. Items installed in the Soft Trim area include glass (the windshield and quarter glass are installed robotically), center console, carpet, and seats. This is also the area where the assembled doors and liftgate are reinstalled. Because many of these installation procedures are repetitive, yet done by hand, GM has worked hard to devise ways to make each job easier and safer. For instance, this worker glides into the moving vehicle while seated on a trick device that eliminates the need to physically climb into each vehicle and install the product. Further, a substantial amount of work was incorporated into the design of the vehicle in an effort to aid in its assembly.

26. This is the proverbial end of the line as far as assembly goes. From here, each vehicle undergoes a significant number of quality checks. Included is a Dynamic Vehicle Test (DVT) that powers the vehicle and tests all of its running systems including engine, transmission, brakes, and so on. There's also a squeak/rattle test and a water test among other things. Once the vehicle passes these tests it's staged for shipment to the dealer.

The Janesville assembly plant, located 105 miles northwest of Chicago, has a long and storied history. It was originally founded in 1919 by GM to produce Samson tractors, but by April of 1929, the plant had produced more than 500,000 cars. During World War II, the plant ceased vehicle production and was used to produce over 16 million 105mm Howitzer and other shells, among other things. Production of cars and trucks resumed in 1946. Over the years, Janesville assembled the "B-body" Caprice/Impala, the "J-body" Cavalier/Skyhawk, medium-duty trucks as well as motorhome and school-bus chassis. In 1991, the plant began producing the GMT400 SUV vehicles. In 1992, the Chevy Blazer won Four Wheeler's Four Wheeler of the Year award and even though GM was suffering through a recession period, Janesville employees worked 5-6 day workweeks to meet demand.

Today the plant encompasses 137 acres and boasts more than 4.8 million square feet. It is home to 2,800 hourly employees and 220 salaried employees. This translates to a stunning payroll of 1 million dollars per day. Currently, 50 GMT900 SUVs roll off the end of the assembly line every hour.

If you would like a free tour of the facility (and we'd highly recommend it), make your reservations by calling the Tour Hotline at 608/756-7681. Each tour is led by a knowledgeable retired employee. Tours begin at 9:15 a.m., 10:45 a.m., and 1 p.m. Monday through Thursday.