Maintaining a full-size Chevy or GMC truck doesn’t have to be complicated — but ignoring the schedule leads to expensive repairs. Here’s a practical maintenance schedule for gas-powered 1/2-ton and 3/4-ton trucks.
Every Oil Change (~5,000 Miles or Per OLM)
- Engine oil and filter (see fluid specs thread for correct weights)
- Visually inspect for leaks under the truck
- Check all fluid levels: coolant, brake fluid, power steering (if applicable), washer fluid
- Check tire pressure (cold)
- Inspect wiper blades
Oil recommendation: Full synthetic Mobil 1 5W-30 for most gas trucks 1999+. The Mobil 1 5W-30 5-quart jug is one of the best-value full synthetic options.
Every 15,000–20,000 Miles
- Rotate tires (unless directional)
- Inspect brakes — pad thickness and rotor condition
- Inspect suspension — ball joints, tie rods, sway bar links
- Lubricate grease fittings (if present — many modern trucks are sealed)
- Inspect air filter — replace if dirty
Every 30,000 Miles
- Replace engine air filter
- Inspect fuel filter (replace if vehicle uses an inline serviceable filter)
- Inspect spark plugs (iridium plugs may go 60K+; platinum go 30K–60K; copper go 15K–30K)
- Transmission fluid drain and fill (4L60E, 6L80, etc.) — use correct spec fluid
- Transfer case fluid — drain and refill with Autotrak II or equivalent
- Front/rear differential fluid — drain and refill per spec
- Inspect CV boots (4WD)
- Inspect cooling system hoses and clamps
Every 60,000 Miles
- Spark plugs (if not done at 30K; iridium plugs on modern EcoTec3s)
- Engine coolant flush and refill (use Dex-Cool or appropriate spec)
- Inspect timing chain/belt (timing chain on most modern V8s; check for stretch)
- Replace throttle body if it has never been cleaned (T-Body cleaning every 60K is good practice)
- Brake fluid flush (especially in humid climates — brake fluid absorbs moisture)
Every 100,000 Miles
- Full cooling system inspection (water pump, thermostat, hoses)
- Inspect all engine and trans mounts
- Transmission rebuild evaluation (have fluid analyzed if concerned)
- Front suspension rebuild if not done — ball joints, tie rods
When to Deviate from Schedule
Towing or severe duty: Shorten all intervals by 30–50% (especially oil and trans fluid)
Northern climate / rust belt trucks: Inspect suspension and brake components more frequently
High-mileage trucks: More frequent oil changes, especially if any burning is detected