GMC 1996 Sierra Owner's Manual page 364

Long Trip/Highway Maintenance Schedule
--
Gasoline Engines
75,000 Miles (125 000 km)
0
Change engine oil and filter (or every
12
months, whichever occurs first).
An Ernission Control Service.
0
Lubricate chassis components; see footnote #
(or every 12 months, whichever occurs first).
0
Check readfront axle fluid level and add
fluid as needed. Check constant velocity
joints and axle seals for leaking.
**
0
Vehicles With GVWR Above 8,500 lbs.
Only: Inspect shields and underhood
insulation for damage or looseness. Adjust
or replace as required.
This is a Noise Emission
Control Service. Applicuble only to vehicles sold in
the United States.
0
If your engine has a thermostatically
controlled cooling fan, inspect all hoses
and ducts for proper hook-up (or every
12 months, whichever occurs first). Be sure
the valve works properly.
This is
a
Noise
Emission Control Service. Appliccrble only to
vehicles sold in the United States.
DATE ACTUAL MILEAGE SERVICED B Y
7-38