GMC 2003 Yukon Owner's Manual page 476

50,000 Miles (83 000 km)
Change automatic transmission fluid and filter if the
vehicle's GVWR is over 8600 lbs or if the vehicle is
mainly driven under one or more of these conditions:
− In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
− In hilly or mountainous terrain.
− When doing frequent trailer towing.
− Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the fluid and filter at 100,000 miles
(166 000 km).
Change transfer case fluid.
52,500 Miles (87 500 km)
Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
Rotate tires. See Tire Inspection and Rotation on
page 5-62 for proper rotation pattern and additional
information. (See footnote +.)
6-8
60,000 Miles (100 000 km)
Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
Rotate tires. See Tire Inspection and Rotation on
page 5-62 for proper rotation pattern and additional
information. (See footnote +.)
Replace fuel filter. An Emission Control Service. (See
footnote †.)
Replace engine air cleaner filter on vehicles without
a restriction indicator. If equipped with a change
indicator, inspect the indicator. If necessary, replace
the filter. If vehicle is driven in dusty/dirty conditions,
inspect the change indicator (if equipped) at every
engine oil change. See Engine Air Cleaner/Filter on
page 5-21 for more information. An Emission
Control Service. (See footnote †.)
Inspect Evaporative Control System. Check all fuel
and vapor lines and hoses for proper hook-up,
routing and condition. Check that the purge valve
works properly, if equipped. Replace as needed. An
Emission Control Service. (See footnote †.)