The 2021 Chevrolet Silverado 1500 belongs to the T1XX generation (2019-present), built with 2.7L Turbo, 4.3L V6, 5.3L V8, 6.2L V8, or the 3.0L Duramax inline-six diesel. It takes 0W-20 full synthetic, in a diesel-rated spec on the Duramax. Oil changes run 7,500 - 10,000 miles, shorter on the diesel under load. This sits in the middle of the generation run, generally the most sorted point in a design before end-of-run cost reductions.
A 2021 Chevrolet Silverado 1500 is 5 years old in 2026, which at an average 12,000 miles a year puts it around 60,000 miles - the interval that decides its future. At roughly 60,000 miles the bigger fluids come due - transmission, differential, coolant - and this is the window that separates vehicles that reach 200,000 miles from those that do not. Deferring here is what produces expensive failures later. On that mileage estimate it should already have had transmission or CVT fluid, differential fluid and brake fluid at 60,000 miles, and the next milestone is 90,000 miles - a second transmission service, suspension inspection and belts - roughly 2.5 years away at average use.
The fault most worth knowing about on this generation is Diesel emissions system faults on low-mileage, short-trip Duramax trucks. Owners also report Lifter failures continued into early Dynamic Fuel Management engines, improving over the run; and 8-speed transmission shudder on earlier builds of this generation. None of these are certainties on any individual vehicle - they are the patterns worth checking for when you buy or when a symptom appears.
Track your 2021 Chevrolet Silverado 1500 service history free with the ServiceSage maintenance tracker, or compare it against other model years on the Chevrolet Silverado 1500 maintenance schedule hub.
| Interval | Service |
|---|---|
| Per GM OLMS (every 7,500-10,000 mi typical) | Engine oil change with dexos1 Gen 3 0W-20 (gas) or dexos D 0W-20 (diesel), Replace oil filter (ACDelco PF63E or equivalent), Reset OLMS oil life indicator, Check tire pressure |
| Every 7,500 mi | Tire rotation, Visual inspection of brakes, suspension, steering components, Inspect CV axle boots and U-joints, Inspect exhaust system and heat shields |
| Every 5,000 mi (3.0L Duramax diesel only) | Check and top off Diesel Exhaust Fluid (DEF) reservoir - approx. 1 gal per 5,000 mi, Inspect fuel/water separator; drain if indicated |
| Every 25,000 mi | Replace cabin air filter, Inspect serpentine belt and tensioner, Lubricate door hinges and hood latch |
| Every 30,000 mi | Inspect engine air filter; replace if dirty or at 45,000 mi, Inspect 4WD front axle and transfer case fluid levels, Inspect brake fluid - flush if moisture-contaminated or at 36 months |
| Every 45,000 mi (severe duty: towing, trailer, off-road) | Transmission fluid drain-and-fill with Dexron HP ATF (severe duty), Front differential fluid change (75W-85 or equivalent GM spec), Rear differential fluid change (75W-85 synthetic), Transfer case fluid change (Auto-Trak II or GM Transfer Case Fluid) |
| Every 100,000 mi | Spark plug replacement (gas only) - ACDelco Iridium or OEM spec, Transmission fluid flush (normal-duty), Coolant system inspection; flush at 150k or 5 years, Inspect drive belt; replace if cracked or worn |
| Every 150,000 mi | Engine coolant flush - replace with GM Dex-Cool (orange), Inspect water pump and thermostat, Diesel fuel injector inspection (3.0L Duramax) |
The table above is indexed by service interval. This is the same schedule indexed by odometer reading, for when you know your mileage and want the list. If your odometer sits between these figures, work back to the last one you passed and catch up anything skipped.
| Odometer | Service due |
|---|---|
| 30,000 mi (48,000 km) | Tire rotation, Visual inspection of brakes, suspension, steering components, Inspect CV axle boots and U-joints, Inspect exhaust system and heat shields, Inspect engine air filter; replace if dirty or at 45,000 mi, Inspect 4WD front axle and transfer case fluid levels, Inspect brake fluid - flush if moisture-contaminated or at 36 months. |
| 60,000 mi (97,000 km) | Same as the 30,000 mi service. |
| 100,000 mi (161,000 km) | Replace cabin air filter, Inspect serpentine belt and tensioner, Lubricate door hinges and hood latch, Spark plug replacement (gas only) - ACDelco Iridium or OEM spec, Transmission fluid flush (normal-duty), Coolant system inspection; flush at 150k or 5 years, Inspect drive belt; replace if cracked or worn. The every-7,500 mi service runs on its own cycle - the nearest fall at 97,500 and 105,000 miles. |
| 120,000 mi (193,000 km) | Same as the 30,000 mi service. |
| 150,000 mi (241,000 km) | Tire rotation, Visual inspection of brakes, suspension, steering components, Inspect CV axle boots and U-joints, Inspect exhaust system and heat shields, Replace cabin air filter, Inspect serpentine belt and tensioner, Lubricate door hinges and hood latch, Inspect engine air filter; replace if dirty or at 45,000 mi, Inspect 4WD front axle and transfer case fluid levels, Inspect brake fluid - flush if moisture-contaminated or at 36 months, Engine coolant flush - replace with GM Dex-Cool (orange), Inspect water pump and thermostat, Diesel fuel injector inspection (3.0L Duramax). |
| 200,000 mi (322,000 km) | Same as the 100,000 mi service. The every-7,500 mi service runs on its own cycle - the nearest fall at 195,000 and 202,500 miles. |
| Fastener | Torque | Size |
|---|---|---|
| Lug nut | 140 ft-lbs (190 Nm) | 22mm (13/16") |
| Oil drain plug | 18 ft-lbs (25 Nm) | 15mm |
| Spark plug | 15 ft-lbs (20 Nm) | 5/8 in. (16mm) |
The 2021 Chevrolet Silverado has 8 safety recalls on record with NHTSA, affecting the seat belts, tires, air bags (as of 2026-07-09). Recall repairs are free at any dealer.
Maintenance keeps these away, but when the dash does light up these are the codes this vehicle throws most often - each with what it means and what the repair actually costs.