Chevrolet 1998 Express Van Owner's Manual page 341

Long Trip/Highway Maintenance Schedule
--
Gasoline Engines
30,000 Miles (50 000 km) (Continued)
0
Replace fuel filter.
An Emission Control Service. (See footnote?.)
17
Replace air cleaner filter.
An Emission Control Service.
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. Applicable only to vehicles sold in the
United States.
37,500 Miles (62 500 km)
0
Change engine oil and filter (or every 12 months, whichever occurs first).
An Emission Control Service.
0
Lubricate chassis components (or every 12 months, whichever occurs first).
0
Check axle fluid level and add fluid as needed. (See footnote
**.)
0
Rotate tires. See "Tire Inspection and Rotation'' in the Index for proper
rotation pattern and additional information. (See footnote
+.)
(See footnote
#.)
MILEAGE
7-30