Chevrolet 2010 Tahoe Owner's Manual page 460

Then, without shutting off the engine, follow these
steps:
See Engine Compartment Overview on page 6 16
for more information on location.
2. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Push it back in all the way, wait three seconds and
then pull it back out again.
1. Locate the
transmission dipstick
handle with this
graphic which is
located at the rear of
the engine
compartment, on the
passenger side of the
vehicle.
4. Check both sides of the dipstick, and read the
lower level. The fluid level must be in the COLD
area, below the cross-hatched area, for a cold
check or in the HOT or cross-hatched area for a
hot check. Be sure to keep the dipstick pointed
down to get an accurate reading.
5. If the fluid level is in the acceptable range, push
the dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least twice using the
procedure described previously. Consistency
(repeatable readings) is important to maintaining proper
fluid level. If readings are still inconsistent, contact your
dealer.
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