GMC X31 Package: What Do You Actually Get?

The GMC X31 package is an available off-road package for the GMC Sierra that adds functional upgrades like all-terrain tires, Rancho® off-road suspension, skid plates, a two-speed transfer case, an automatic locking rear differential, and Hill Descent Control. Unlike the Sierra AT4, the X31 package improves off-road capability without adding a factory suspension lift.

What Is the GMC X31 Package?

The GMC X31 package is an available off-road equipment package for select GMC Sierra 1500 models. It is designed for drivers who want extra capability for conditions like gravel roads, snow, mud, trails, and uneven terrain while still maintaining the everyday comfort of a Sierra.

One important detail: the X31 package does not include a factory suspension lift. If you’re looking for increased ride height and more aggressive off-road equipment, the Sierra AT4 is the model designed for that purpose. The X31 package takes a different approach by adding key performance and protection upgrades while keeping the truck’s standard ride height.

Exterior and Protection Upgrades

The GMC X31 package includes several upgrades that improve more than just the truck’s appearance. Each feature is designed to add confidence when the road gets rough.

All-Terrain Tires

The most noticeable upgrade is the addition of factory all-terrain tires. Compared to standard road-focused tires, all-terrain rubber provides improved traction on loose surfaces like gravel, dirt, mud, and snow while still maintaining comfortable on-road manners.

Front Skid Plates

Off-road driving exposes a truck’s underbody to rocks, ruts, and debris. The X31 package adds front skid plates designed to help protect important components underneath the Sierra when traveling over rough terrain.

Heavy-Duty Engine Air Filter

Dusty trails and unpaved roads can introduce more debris into the engine’s air intake system. The heavy-duty engine air filter helps improve filtration in these conditions, helping protect engine performance during off-road driving.

X31 Exterior Enhancements

Every GMC Sierra equipped with the X31 package receives exclusive X31 badging. Depending on the trim level, additional appearance upgrades may include unique wheels, trim accents, and other styling details that give the truck a more rugged look.

Suspension and Mechanical

The GMC X31 package is not just about appearance. Some of its most important upgrades are found underneath the truck.

Rancho® Twin-Tube Shocks

The X31 package includes Rancho® twin-tube shocks that are tuned to handle rougher terrain while maintaining a comfortable ride during everyday driving.

These upgraded shocks help improve control over uneven roads and trails. However, they are different from the Rancho monotube shocks equipped on the factory-lifted Sierra AT4.

Essential Off-Road Functionality

Where the GMC X31 package really stands out is in the drivetrain and technology designed to help the Sierra perform in low-traction situations.

1. Two-Speed Autotrac® Transfer Case

The available two-speed Autotrac transfer case gives drivers access to both 4-High and 4-Low settings.

While 4-High is useful for maintaining traction on slippery roads, 4-Low provides additional torque for slow-speed situations like steep climbs, deep mud, loose terrain, and challenging trails.

2. Automatic Locking Rear Differential

One of the most valuable features included with the GMC X31 package is the automatic locking rear differential.

When one rear wheel begins to lose traction, the system helps distribute power more effectively by locking the rear axle together. This allows both rear wheels to work together, helping the truck maintain momentum in slippery or uneven conditions.

3. Hill Descent Control

Steep downhill sections can be just as challenging as uphill climbs. Hill Descent Control helps manage vehicle speed by automatically applying braking when needed, allowing the driver to focus on steering and choosing the best path forward.

GMC X31 Package vs. AT4: What’s the Difference?

The GMC X31 package and the Sierra AT4 are both designed for drivers who want more off-road capability, but they are built for different needs.

The X31 package is ideal for drivers who want additional confidence for weekend adventures, changing weather conditions, gravel roads, and light trail use. It adds key upgrades like all-terrain tires, off-road suspension components, skid plates, and drivetrain enhancements without changing the truck’s ride height.

The Sierra AT4 takes things further with a factory suspension lift, increased ground clearance, Rancho monotube shocks, and additional equipment designed for more serious off-road driving.

For many Sierra owners, the GMC X31 package offers the right balance of capability and everyday practicality.