GMC 2010 GMC Sierra, Owner'S Manual

Page: 488 / 660

Automatic Transmission Fluid
(6-Speed Transmission)
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 overheating the transmission.
If you suspect a small leak, 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's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7 ‑ 13 .
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See
Scheduled Maintenance
on page 7 ‑ 3 . Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants on
page 7 ‑ 13 .
How to Check Automatic Transmission
Fluid
Notice: Too much or too little fluid can damage the
transmission. Too much can mean that some of the
fluid could come out and fall on hot engine parts
or exhaust system parts, starting a fire. Too little
fluid could cause the transmission to overheat.
Be sure to get an accurate reading if checking the
transmission fluid.
Before checking the fluid level, prepare the vehicle as
follows:
1. Start the engine and park the vehicle on a level
surface. Keep the engine running.
2. Apply the parking brake and place the shift lever in
P (Park).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, move the shift
lever back to P (Park).
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