1993 GMC Sonoma Owner's Manual - Page 325

5. AIR CLEANERFILTERREPLACEMENT* -Replaceatspecified intervals.Askyourdealerfortheproperreplacementintervalsforyour drivingconditions. 6. FRONTWHEELBEARINGREPACK(2-WHEELDRIVEONLY) -Clean andrepack the frontwheelbearingsateachbrakerelining,oratthe specifiedinterval,whichevercomesfirst. 7. TRANSMISSIONSERVICE: AutomaticTransmission -Change the transmissionfluidandfilterevery 15,000miles(25 000 km) if thevehicleismainlydrivenunderoneor more of theseconditions: In heavycitytraffic. Wheretheoutsidetemperatureregularlyreaches higher. Inhillyormountainousterrain. Frequenttrailerpulling. Usessuchastaxi,police,deliveryorothercommercialservice. If the vehicleisnotusedmainlyunderany of theseconditions,change thefluidandfilterevery30,000miles (50 000 km).See"Automatic TransmissionFluid" in the Indexformoreinformation. 90°F (32°C) or ManualTransmission -Transmissionfluiddoesnotrequireperiodic changing. 8. FUELFILTERREPLACEMENT* intervalorsooner if clogged. -Replacethefuelfilterat the specified 9. SPARKPLUGSREPLACEMENT* -Replacesparkplugswiththetype listed in Section 6. See"SpecificationCharts"intheIndex. 10. SPARK PLUGWIREINSPECTION* -Cleanwiresandinspectforburns, cracksorotherdamage.Checkthewireboot fit atthedistributorandat thesparkplugs.Replacewiresasneeded. -Adjusttiming 11. ENGINETIMINGCHECKANDDISTRIBUTORCHECK* to underhoodlabelspecifications.Inspecttheinsideandoutside of the distributorcapandrotorforcracks,carbontrackingandcorrosion.Clean orreplaceasneeded. 12. FUELTANK,CAPANDLINESINSPECTION* -Inspectthefueltank, capandlinesfordamageorleaks.Removefuelcap,inspectgasketfor anevenfillerneckimprint,andanydamage.Replacepartsasneeded. * AnEmissionControlService 7-9