ServlogUpdated 2026-07-02
GMC Sierra 1500 Transmission Fluid: Change Interval
Compiled & reviewed by Nikolai Tsyrenov · Updated 2026-07-02
When to change the transmission fluid on a 2019-2024 (T1XX) GMC Sierra 1500.
In short: GMC Sierra 1500 transmission fluid: ~45,000 mi normal / ~30,000 mi severe (towing).
| Transmission Fluid interval | ~45,000 mi normal / ~30,000 mi severe (towing) |
|---|---|
| Engine / drivetrain | 5.3L/6.2L V8, 2.7L turbo or 3.0L Duramax diesel; dexos1 0W-20; 8- or 10-speed auto |
| Model years | 2019-2024 (T1XX) |
Why it matters: Transmission fluid lubricates and cools the gearbox. "Lifetime fill" really means "lifetime of the warranty" — heat from towing, hills and stop-and-go traffic ages it much faster.
A drain-and-fill (not a flush) is the safe approach, especially on higher-mileage cars. Use ONLY the exact fluid spec for your transmission — the wrong fluid can ruin a CVT or automatic.
GMC Sierra 1500 note: Mechanically the twin of the Chevy Silverado 1500 — same engines, same unusually short transmission-fluid interval (~45k / 30k severe) and AFM/DFM caution on the V8s.
FAQ
How often should you change the transmission fluid in a GMC Sierra 1500?
~45,000 mi normal / ~30,000 mi severe (towing).
Should I flush or drain-and-fill the transmission on a GMC Sierra 1500?
Prefer a drain-and-fill. A pressure flush on an old, never-serviced transmission can dislodge debris; a simple drain-and-fill (repeated if needed) is the gentler, widely recommended option.
Where can I check all GMC Sierra 1500 service intervals?
The full GMC Sierra 1500 maintenance schedule covers oil, tires, fluids, filters and major milestones for the 2019-2024 (T1XX) model years.
← Full GMC Sierra 1500 maintenance schedule · Transmission Fluid intervals for all cars
General guidance — confirm against your GMC Sierra 1500 owner's manual.
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