The architecture underlying the T1-generation 2021 Chevrolet Tahoe and Suburban will eventually support some of the most profitable vehicles GM sells, and in the face of newly stiffened competition from the Ford Expedition and Lincoln Navigator, the General has pulled out all the “stops” on their engineering “organ.” Here are seven T1 tech highlights for you to memorize and play back at this season’s holiday parties with your car pals:
All (98%) New
Relative to the outgoing K2 models, 98 percent of the T1 Tahoe and Suburban is new. Outside, it’s basically everything but the windshield; inside everything but the steering wheel. There’s also less of the new model shared with the pickup truck it’s based on than usual, though the forward part of the frame and much of the body crush structure up there is shared, along with most of the steering and suspension hard parts (bushings are all optimized for the SUVs). An exception is the lower control arms, which feature a cross bar missing on the Silverado (making them A-arms, not V-arms).
Bonus Benefits of IRS
You already know that the independent rear suspension (IRS) promises improved ride comfort, sharper handling, and increased passenger and cargo packaging space. That last benefit, of course, is because the load floor could be lowered by as much as 5.3 inches because the bulky differential “pumpkin” no longer bobs around on a live axle, but instead gets mounted to the chassis. That crossmember it mounts to has a much taller structural “section” that adds rigidity to the frame. And because there’s now so little movement between the differential and transmission or transfer case, the driveshaft doesn’t require as extensive a “plunge joint” as its predecessor (of course, the two rear half-shafts now need plunge joints).
The compressed air filling those new optional springs is supplied by a small compressor attached using very compliant rubber mounts back near the spare tire. It fills a reservoir that sits below the right middle-row passengers’ feet next to the transfer case.
Adding just the air suspension and fourth-gen magnetorheological shocks alone would have overwhelmed the computing power onboard the previous-generation K2 architecture, let alone the SUVs’ 30 available safety and driver-assist systems. So the new Tahoe and Suburban have the ability to process 4.5 terabytes of information per hour—a five-fold increase over the previous generation. That’s 4.5 x 1012 bytes—equivalent to 980 movies. Speaking of which, giant 12.6-inch rear seat displays are now available along with an available 10-inch diagonal central infotainment screen, an 8.0-inch digital cluster, and a head-up display, which at 15 inches is a claimed class-leader. All cameras are upgraded to high-def 1-megapixel standards, and over-the-air updates will be available for much of this, leveraging the onboard 4G cellular connection. Naturally we’re assured the latest cybersecurity measures are in place to thwart would-be hackers, including message-authentication and numerous “gateways” isolating the various busses and onboard networks.
The previous-generation Tahoe/Suburban bodies were quasi-unitized from the firewall back, with the front structure bolted on, but the new T1 “body-in-white” includes the front crash structure welded in. This simplifies assembly somewhat and improves crash performance.
How the Sausages Get Made
A single plant in Arlington, Texas, builds all Tahoes and Suburbans for distribution to 31 countries with a capacity of 240,000 per year. A $1.4 billion investment there has added a new 1-million-square-foot body shop and a 600,000-square-foot paint shop. The body shop gets 1,450 new robots and can now stamp aluminum panels (which include the hood, doors, and liftgate) as well as steel, employing automated robotic die-swaps that now take minutes instead of hours. The paint shop gets a new thin-film metal prep process that’s way more environmentally friendly than the former acid etching system. Also earth-friendly: The water-borne final paint process. The new body shop will clearly ease the transition from K2 to T1 generation production and allows the old body shop to eventually be repurposed to add capacity, or another model in years to come. Other manufacturing upgrades: The body’s “marriage” to the chassis (via 10 mounting points) is now fully automated as is the aiming and alignment process for the new LED headlamps. The new liftgate inner and outer panels can be stamped in a single operation (the predecessor required brazing of multiple pieces).
Tighter Mechanical LSD
A new mechanical limited-slip device supplied by American Axle operates with clutch packs designed with a certain preload that lock up above a certain left-right wheel-speed differential. The previous Eaton G80 differential behaved like an open diff until one wheel began spinning, which then locked the axle. This new differential attaches to the frame via one mount in front and two in the rear.