Automatic transmission fluid (Chevrolet Tahoe 1)

How to check and replace

A good time to check your automatic transmission fluid level is when you change your engine oil.

Change the fluid and filter every 50,000 miles (83,000 km) if the vehicle is primarily used under the following conditions:

• When driving in severe urban conditions where the air temperature is regularly 90°F (32°C) or higher
• In hilly and mountainous areas
• When you tow a trailer frequently
• Use your car as a taxi, police car or delivery service.

If you do not use the vehicle under these conditions, the fluid and filter do not require replacement.

How to check

Since this operation is a bit complicated, you can have it done by the GM service department (General Motors).

If you want to do it yourself, follow all the instructions here or you will get incorrect data on the dipstick.

Note: Too much or too little fluid can damage the transmission.

Wait at least 30 minutes before checking the fluid level if you have been driving:

• When the outside air temperature is above 90°F (32°C).
• At high speed for quite a long time.
• In heavy traffic conditions - especially in hot weather.
• If you were pulling a trailer.

To obtain correct readings, the fluid must be at normal operating temperature between 180°F (82°C-93°C).

Checking the liquid is hot

Warm up the vehicle by driving it approximately 15 miles (24 km) when the outside temperature is above 50°F (10°C).



If it is colder than 10°C, drive the vehicle in 3rd gear until the engine temperature gauge moves and remains steady for 10 minutes.

Then proceed with the hot check procedure.

Checking the liquid cold

A cold check is done when the vehicle has been parked for eight hours or more with the engine off and is for reference only. Let the engine idle for 5 minutes if the air temperature is 50°F (10°C) or above. If below 10°C, let the engine idle longer. If the fluid level is low during a cold check, you should do a hot check before adding fluid.

This will give you more accurate fluid level readings.

Checking the fluid level hot or cold

Park your car on a level place. Keep the engine running.

With the parking brake applied, place the gear shift lever in PARK (P).

Without removing your foot from the brake pedal, move the gearshift lever through each gear, holding each gear for about 3 seconds. Then return the gearshift lever to P.

Let the engine idle for three minutes or more.



Then, without turning off the engine, do the following:

• 1. The red transmission dipstick is located behind the engine compartment on the passenger side. Lift the handle, pull out the dipstick and wipe it with a rag or paper towel.
• 2. Put it back in, wait three seconds and pull it out again.
• 3. Check both sides of the dipstick, look at the bottom level. The fluid level should be in the COLD area for a cold check and in the HOT area or the cross-marked area for a hot check.
• 4. If the fluid level is within acceptable limits, reinsert the dipstick completely, then snap the handle down to lock the dipstick in place.

How to add liquid

Determine what grade of transmission fluid you want to add. We recommend DEXRON-III only. Add liquid only after a hot test. If the liquid level is low, add the appropriate liquid in the required amount so that the level rises to the NOTES of the platform during a hot check. This will not require much liquid, usually less than one pint (0.5 liters). Don't overfill it.

After adding fluid, recheck the fluid level.