1993 GMC Safari Owner's Manual - Page 317

6. TRANSMISSIONSERVICE Changethetransmission fluid andfilterevery15,000miles(25 000 km). If the vehicle is mainly driven under one or more oftheseconditions: In heavy city traffic. Wheretheoutsidetemperatureregularlyreaches higher. In hilly ormountainousterrain. Frequenttrailerpulling. Usessuchastaxi,police,deliveryorothercommercialservice. If thevehicle is notusedmainlyunderany of theseconditions,change the fluid andfilterevery 30,000 miles (50 000 km).See"Automatic TransmissionFluid" in theIndexformoreinformation. 7. FUELFILTERREPLACEMENT* interval orsooner if clogged. 90°F (32°C) or -Replace thefuelfilteratthespecified 8. SPARKPLUGSREPLACEMENT* -Replacespark plugswith the type listed in Section 6. See"SpecificationCharts" in theIndex. 9. SPARKPLUGWIRE INSPECTION* -Cleanwiresand inspectforburns, cracksorotherdamage.Checkthewirebootfitatthedistributorandat thesparkplugs.Replacewires as needed. -Adjust timing to 10. ENGINETIMINGCHECKANDDISTRIBUTORCHECK underhood label specifications.Inspecttheinsideandoutside of the distributorcapandrotorforcracks,carbontrackingandcorrosion.Clean or replaceasneeded. -Inspect the fuel tank, 11. FUELTANK,CAPANDLINESINSPECTION* capandlinesfordamageorleaks.Removefuelcap,inspectgasketfor anevenfillerneckimprint,andanydamage.Replacepartsasneeded. -Inspect 12. ENGINEACCESSORYDRIVEBELTINSPECTION* forcracks,fraying, wear,and propertension.Adjustorreplace needed. * AnEmissionControlService belt.Look as 7-9