GMC 2011 Sierra - Manual (Page 546)

Black plate (6,1) GMC Sierra Owner Manual - 2011
11-6 Service and Maintenance
First Engine Oil Change After
Every 40 000 km/25,000 Miles
. Four‐wheel drive only: Transfer
case fluid change (extreme duty
service) for vehicles mainly
driven off‐road in four‐wheel
drive. Vehicles used for farming,
mining, forestry, Department of
Natural Resources (DNR), and
snow plowing occupations meet
this definition. Check vent hose
at transfer case for kinks and
proper installation. Check to be
sure vent hose is unobstructed,
clear, and free of debris. During
any maintenance, if a power
washer is used to clean mud
and dirt from the underbody,
care should be taken to not
directly spray the transfer case
output seals. High pressure
water can overcome the seals
and contaminate the transfer
case fluid. Contaminated fluid
will decrease the life of the
transfer case and should be
replaced.
First Engine Oil Change After
Every 80 000 km/50,000 Miles
. Engine air cleaner filter
replacement. See Engine Air
Cleaner/Filter on page 10‑19.
. Automatic transmission fluid
change (severe service) for
vehicles with Gross Vehicle
Weight Rating (GVWR) over
3 901 kg (8,600 lbs) or mainly
driven in heavy city traffic in hot
weather, in hilly or mountainous
terrain, when frequently towing
a trailer, or used for taxi,
police, or delivery service.
See Automatic Transmission
Fluid (4-Speed Transmission) on
page 10‑13 or Automatic
Transmission Fluid (6-Speed
Transmission) on page 10‑16.
. Four‐wheel drive only: Transfer
case fluid change (severe
service) for vehicles mainly
driven when frequently towing
a trailer, or used for taxi, police,
or delivery service. Check
vent hose at transfer case for
kinks and proper installation.
Check to be sure vent hose is
unobstructed, clear, and free of
debris. During any maintenance,
if a power washer is used to
clean mud and dirt from the
underbody, care should be taken
to not directly spray the transfer
case output seals. High pressure
water can overcome the seals
and contaminate the transfer
case fluid. Contaminated fluid
will decrease the life of the
transfer case and should be
replaced.