GMC Sierra Large-Wheel Tires, Ride and Truck Care

Upper Sierra trims often use 20- or 22-inch wheels with low-profile tires. A large, heavy wheel and tire assembly magnifies small imbalances, and a short sidewall gives little protection from potholes. A bent rim or a tire with a stiff spot can cause a shake that a standard balance does not cure.

We check for:

• Lost or shifted wheel weights
• Wheel runout from a pothole hit
• Tire uniformity problems
• Loose or worn steering parts that amplify vibration

Road force balancing presses a roller against the tire to find stiff spots, then matches the tire to the wheel for the smoothest ride. It is especially useful on large truck wheels.

AT4 trims come from the factory with a raised stance and all-terrain tires. Those tires handle dirt and gravel well, but on pavement they are louder and can develop uneven tread blocks without regular rotation.

• Rotate on schedule to keep tread blocks wearing evenly
• Check pressure cold, and adjust after trail use
• Inspect for chunking and cuts after rocky trips
• Match replacements to the load rating on the placard

If most of your driving is pavement, we can compare a highway-leaning all-terrain with a more aggressive one. See new tires and brands.

Depending on year and trim, a Sierra may have conventional shocks, adaptive dampers or an air suspension system. Adaptive and air systems need care when lifting and aligning, following the service procedures in the owner's manual.

We print before and after alignment numbers. On factory-raised or aftermarket-lifted trucks, we tell you if the current parts reach spec. Driver-assist cameras on newer Sierras may need attention after ride-height changes, and we note that when it applies.

Sierras often tow boats, campers and equipment. Towing adds brake heat and puts extra weight on rear tires. We measure pads and rotors, check fluid, and inspect the hitch, ball, pin, chains and trailer lights.

See towing and hauling for more.

Yes for routine maintenance. Sierra 1500 engines include turbo four-cylinders, V8s and a light-duty diesel depending on the year. Each needs its correct oil specification. Diesels also need fuel filter and fuel-water separator attention. See diesel maintenance.

A few habits help any Sierra engine last:

• Follow the oil life monitor, and shorten the interval when towing in summer heat
• Keep the engine air filter clean, especially after dusty job sites or desert trips
• Check coolant hoses and the radiator before towing season
• On diesels, drain water from the fuel system as the manual directs

We note the oil specification and the next service reminder on your invoice so the next visit is easy to plan.

Judge a used Sierra by its wheels, suspension, drivetrain and records, not just the trim badge and mileage. Big wheels hide pothole damage, and towing history is not always obvious. An inspection before you buy shows what the truck needs now and what you can plan for later.

What we pay attention to on used Sierras:

1. Wheel runout and tire bulges, especially on 20- and 22-inch packages
2. Lifter or valvetrain noise on V8 trucks with cylinder deactivation. Owners of some model years have reported lifter trouble, so an irregular tick or a misfire code deserves a proper diagnosis.
3. Shift quality: harsh or late shifts, or a shudder at steady speed
4. Air suspension or adaptive damper warnings on equipped trims
5. Diesel records: fuel filter changes and exhaust fluid system health
6. Brake controller and hitch wiring that show how hard the truck worked

We scan codes, road test and photograph what we find. It is not a warranty and cannot promise that nothing will fail later. Check open recalls with the VIN at nhtsa.gov/recalls (opens in a new tab). See pre-purchase inspections for the full list.

A Sierra can carry very different weight from one day to the next. The door placard lists the recommended cold pressure, and the owner's manual explains adjustments for heavy loads and towing. LT tires often need higher pressure to carry their rated weight. Set pressure cold, before the trip, for the heaviest load you plan to carry.

Signs a truck has been running underinflated or overloaded:

• Worn outer shoulders on both edges of the tread
• Flex cracks or heat marks on the sidewall
• Wandering on the freeway when loaded

Upper trims with large wheels have less sidewall to absorb an overload, so a pothole under weight is more likely to bend a rim. We check pressure at every visit and can note your loaded setting on the invoice. See our tire pressure and care guide.