GMC 1993 Suburban Owner's Manual page 357

6. AIR CLEANER FILTER REPLACEMENT* -Replace at every 30,000
miles (50 000 km) or more often under dusty conditions. Ask your dealer
for the proper replacement intervals for your driving conditions.
7. FRONT WHEEL BEARING REPACK (2 WHEEL DRIVE ONLY) --Clean
and repack the front wheel bearings at each brake relining, or at the
specified interval, whichever comes first.
8. TRAMSMISSBON SERVICE
Automatic Transmission -Change the transmission fluid and
filter
every
15,000 miles (25
000
km) for vehicles under 8,600 GVWR or every
12,000 miles (20 000 km) for vehicles over 8,600 GVWR if the vehicle
is mainly driven under one or more of these conditions:
Q
In heavy city traffic.
Where the outside temperature regularly reaches
90°F (32°C)
or
higher.
*
In
hilly
or
mountainous terrain.
*
Frequent trailer pulling.
e
Uses such as taxi, police, delivery or other commercial service.
If the vehicle is not used mainly under any
of these conditions, change
the fluid and filter- every 30,000 miles (50 000 km) for vehicles under
8600 GVWR or every 24,000 miles (40 000 km) for vehicles over
8600
GVWR. See "Automatic Transmission Fluid"
in the Index for more
information.
Manual Transmission -Transmission fluid does not require periodic
changing.
Regulator Valve System for any worn, plugged or collapsed hoses. Have
the system checked as described in the Service Manual.
10.
FUEL FILTER REPLACEMENT" --Replace the fuel filter at the specified
interval or sooner if clogged.
9.
CDRV SYSTEM INSPECTION* -Check the Crankcase Depression
11. SPARK PLUGS WEPLACEMENT* --Reglace spark plugs with the type
listed in Section
6.
See "Specification Charts" in the Index.
12. SPARK PLUG WIRE INSPECTION* --Clean wires and inspect for burns,
cracks or other damage. Check the wire boot fit at the distributor and at
the spark plugs. Replace wires as needed.
*An Emission Control Service
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