GMC 1994 Yukon Owner's Manual page 353

7. TRANSMISSION 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:
0
In heavy city traffic.
0
Where the outside temperature regularly reaches YO" F (32
O
C) or
higher.
0
In hilly or mountainous terrain.
0
Frequent trailer pulling.
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
8,600 GVWR or every 24,000 miles (40
000
km) for vehicles over
8,600 GVWR see "Automatic Transmission Fluid" in the Index for
more information.
Manual Transmission
-
Transmission fluid does not require periodic
changing.
8. CDRV
SYSTEM INSPECTION*
-
Check the Crankcase
Depression Regulator Valve System for any worn, plugged or collapsed
hoses. Have the system checked as described in the Service Manual.
9. FUEL FILTER REPLACEMENT*$
-
Replace the fuel filter at the
specified interval or sooner if clogged.
10. SPARK PLUG REPLACEMENT*
~
Replace spark plugs with the
type listed in Section 6. See "Specification Charts" in the Index.
11. 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
$The California Air Resources Board has determined that the failure to
perform this maintenance item will not nullify the emission warranty or
limit recall liability prior to the completion of the vehicle useful life.
General Motors, however, urges that all recommended maintenance
services be performed at the indicated intervals and the maintenance be
recorded.
?A fluid loss in these systems may indicate a problem. Have them
inspected and repaired at once.
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