I shouted to my driving partner, Shad Balch, director of Chevrolet Communications, “Rock left, going to straddle it,” as we were driving about 45 mph and focusing on a rock on the left. Unfortunately, I missed another rock on the right, resulting in a loud bang. The radio crackled, and truck 99 informed me that I was dog tracking in truck 18 and should pull over. I was driving a blue 2023 Chevrolet Colorado ZR2 on a three-day drive from Las Vegas to Reno, using much of the 2023 Best In The Desert Vegas to Reno race course. Despite hearing and feeling a boom from the rear end and seeing an alert for a low right rear tire on the digital gauge cluster, the truck was still driving.
While off-roading, the fear isn’t just about crunched metal, but also what’s broken behind it. The 2023 Colorado ZR2 is more durable, and even if you hit a boulder, the axle will be fine. However, when I got out of the car, it became clear that the rock I straddled shouldn’t have made contact with the bash plates. The driver’s side rear tire had too much camber, and the right rear quarter panel was dented. The right rear Goodyear was flat, and the right rear wheel and tire sat farther back in the wheelwell. The rock had knocked off the rear U-bolt off the top plate after sheering off the centering pin.
Looking underneath, I realized that the rock had struck the aluminum driveshaft, which was dented but still intact just ahead of where it slides into the rear-end. The driveshaft spun the rock back to the right, hitting where the U-bolts hold the axle and leaf spring together. It sheared the pin that centers the mounting bracket top plate with the U-bolts, axle, and leaf spring. As a result, the axle slid back about three inches on the passenger’s side, bending the front U-bolt while shoving the rear U-bolt off the top plate. Even though the truck was in one piece, the axle had to be shoved back into place.
Henry Canan, a GM tech who spends his days fixing the stuff the engineering team breaks during development, was on hand, but the chase truck didn’t have a replacement pin or U-bolts. However, Canan removed the driveshaft, making the ZR2 a front-wheel-drive vehicle momentarily. Chevrolet Performance Manager of Performance Integration Tim Demetrio then put the truck in 4Lo, locked the front locker, shifted into reverse, and backed into a rock placed behind the right rear tire. The axle slid forward and back into place, and Canan slid the U-bolts in backward so they pulled against the axle to keep it centered since there was no replacement centering pin. Canan also installed a steel driveshaft available through Chevrolet Performance, and with a spare wheel and tire, the truck was back in one piece. We turned around and drove out the way we came in.
On the highway, Demetrio asked, “Let me know if that thing pulls, vibrates, or doesn’t feel right, truck 18.” I responded, “Amazingly, it drives… fine. Seems to pull a smidge to the left if anything, but otherwise, it’s fine.” After five days, four hotels, 350 miles off pavement in the desert, and about 400 to 500 more miles on pavement, that’s the worst, and only, thing that happened to any of the ZR2s aside from flat tires, and the truck was still driveable.
The second-generation Chevrolet Colorado ZR2 is the automaker’s flagship off-roader, and its hardware and specs let it brush off jumps, rocks, ruts, mud, water, silt, sand, snow, and everything else we encountered in the desert. The new ZR2 rides on a model-specific frame with additional reinforcements for loads and twist and revised geometry to mount the rear shocks outboard by the wheels instead of inboard like the rest of the standard 2023 Chevrolet Colorado lineup. The Multimatic Dynamic Suspension Spool Valve (DSSV) shocks are among the best off-roading parts on the second-generation ZR2, and they have been upgraded with the rod from the larger Silverado 1500 ZR2 for more damping force and a new tune for more control at speed.
The ZR2 also rolls on a 3.0-inch wider track and has 3.0-inch lift compared to the base Colorado. The numbers speak for themselves with 10.7 inches of ground clearance, and 9.9 inches of front and 11.6 inches of rear suspension travel. These changes contribute to a 24.6-degree breakover angle, a 38.3-degree approach angle, and a 25.1-degree departure angle. The ZR2’s approach and departure angles beat those of the current Toyota Tacoma TRD Pro, but Toyota’s shorter wheelbase pays dividends in the form of a slightly better breakover angle at 26.6 degrees.
The ZR2’s approach, departure, and breakover angles are also all better than those of the Ford F-150 Raptor, regardless of whether it’s on 35s or 37s, and the Ram 1500 TRX. The 2023 Chevrolet Colorado ZR2’s secret sauce is hidden in the fender wells in the form of Multimatic DSSV shocks.
