The Chevrolet Silverado ZR2 and the Mystery of '4WD Off'

With the arrival of the 2022 Chevrolet Silverado ZR2 earlier this year, our selection of gasoline-powered mega-pickups grew to three. While the Chevy gets magical Multimatic DSSV spool dampers and a 6.2-liter V-8, it offers neither the decadent horsepower nor the outrageous pre-runner bodywork of the Ford F-150 Raptor and the Ram 1500 TRX. But the ZR2's narrowness can be seen as an advantage when your off-road environs are more suited to rock bouncers than Best in the Desert events.

Being 5.4 inches narrower than the Raptor and 6.8 inches narrower than the TRX, the ZR2 is scaled for the realities of East Coast trails, where speeds are low and trees are plentiful. A little too plentiful, I might say, after my visit to Uwharrie National Forest, where I accidentally discovered a transfer case mode called "4WD Off" that's been much discussed in GM truck forums. The bad news is that my encounter with 4WD Off led to some light body damage. The good news: if you own a GM truck with a full-time transfer case—an AWD mode—I can now tell you what not to do, and why.

The trails at Uwharrie tend to be tight and steep. I once had to bail early on a drive there in a Toyota Tundra long-bed because it didn't have the breakover angle to crest the tall, steep drainage berms that crisscross the trails. It's definitely not a place you'd want to take a TRX. Even the ZR2, I thought, might be pushing it. You know you're dealing with some tricky terrain when the trails have guardrails.

One problem with Uwharrie is that no matter how many times I go there, as soon as I turn onto the access road I immediately get lost. So, when I aimed the ZR2 toward a trail named Daniel, I ended up on the wrong side of it. Daniel goes up and over a mini-mountain, and from one side it's a challenging but relatively easy climb. The other side . . . is where I ended up. Search "Uwharrie Roll Over" on YouTube and a lot of the results will be right there where I arrived with the ZR2. You can even find a Chevy. Short-wheelbase Jeeps have it particularly tough. It's called The Ledge, and if your truck can't make it up and over, it really has no business getting into the stuff higher up. The only time I've gone up over The Ledge was in an American Expedition Vehicles Jeep Wrangler Unlimited Rubicon with a lift and 35-inch tires.

The ZR2 has 33-inch tires, tame by current standards. But, by virtue of its slimmer front bumper, it has excellent approach angles. In fact, its approach and breakover angles are better than those of both the TRX and the Raptor on its standard tires. The ZR2 is also armored-up with skid plates, and it gets locking differentials front and rear. But not in the middle, as I'll tell you all about.

The ZR2 is basically the perfect size for The Ledge. Its wheelbase is long enough to lend front-to-rear stability when the nose climbs to the sky (a major problem here for the two-door Wranglers), and it's wide enough to straddle the rut that runs along the right side of the approach. With the lockers and serious suspension articulation at the rear axle, the ZR2 idled up and over without much drama, even when at least one tire was usually airborne. While the ZR2 has a one-pedal drive mode for trails, I figured that in this circumstance I'd go with the two-foot method, overlapping brake and throttle to keep the driveline wound up.