Black plate (11,1)
GMC Sierra Owner Manual - 2011
Vehicle Care
10-11
Automatic Transmission
Fluid (4-Speed
Transmission)
When to Check and Change
Automatic Transmission Fluid
A good time to check the automatic
transmission fluid level is when the
engine oil is changed.
Change the fluid and filter at the
intervals listed in
Scheduled
Maintenance on page 11
‑
2
and be
sure to use the transmission fluid
listed in
Recommended Fluids and
Lubricants on page 11
‑
8
.
How to Check Automatic
Transmission Fluid
Because this operation can be a
little difficult, it may be best to have
this done at the dealer service
department.
If not taken to the dealer, be sure to
follow all the instructions here or a
false reading on the dipstick could
result.
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.
Wait at least 30 minutes before
checking the transmission fluid level
if you have been driving:
.
When outside temperatures are
above 32°C (90°F).
.
At high speed for quite a while.
.
In heavy traffic
—
especially in
hot weather.
.
While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by
driving about 24 km (15 miles) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
moves and then remains steady for
10 minutes.
A cold fluid check can be made
after the vehicle has been sitting for
eight hours or more with the engine
off, but this is used only as a
reference. Let the engine run at idle
for five minutes if outside
temperatures are 10°C (50°F) or
more. If it is colder than 10°C
(50°F), the engine may have to idle
longer. Should the fluid level be low
during this cold check, the fluid must
be checked when hot before adding
fluid. Checking the fluid hot will give
you a more accurate reading of the
fluid level.
