When to Check and Change Automatic Transmission Fluid

It is usually not necessary to check the transmission fluid level.

The only reason for fluid loss is a transmission leak or overheated transmission. If a small leak is suspected, then use the following checking procedures to check the fluid level. However, if there is a large leak, then it may be necessary to have the vehicle towed to a dealer service department and have it repaired before driving the vehicle further.

Notice: Use of the incorrect automatic transmission fluid may damage the vehicle, and the damages may not be covered by the vehicle warranty. Always use the automatic transmission fluid listed in Recommended Fluids and Lubricants on page 11‑12.

Change the fluid and filter at the scheduled maintenance intervals listed in Maintenance Schedule on page 11‑3. Be sure to use the transmission fluid listed in Recommended Fluids and Lubricants on page 11‑12.

    See also:

    What to Add
    Use only new DOT 3 brake fluid from a sealed container. See Recommended Fluids and Lubricants on page 11‑12. Always clean the brake fluid reservoir cap and the area around the cap before re ...

    Front Fog Lamp Light
    The fog lamp light comes on when the fog lamps are in use. The light goes out when the fog lamps are turned off. See Fog Lamps on page 6‑5 for more information. ...

    All Terrain chassis and suspension
    Based on the chassis of the 2011 Sierra HD trucks, the All Terrain HD features a fully boxed steel frame with exceptional strength and torsional stiffness. It incorporates the production models' n ...