1993 GMC Safari Owner's Manual - Page 288

Service & Appearance Cam failure.Thegrade C corresponds to alevel ofperformancewhich all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades B and A representhigherlevelsofperformanceon thelaboratorytestwheelthantheminimumrequiredby law. Warning:Thetemperaturegradefor thistireisestablishedforatire that is properlyinflatedandnotoverloaded.Excessivespeed,underinflation,or heat buildup excessiveloading,eitherseparately or incombination,cancause and possible tire failure. Thesegradesaremoldedonthesidewallsofpassengercartires. WhilethetiresavailableasstandardoroptionalequipmentonGeneralMotors vehicles mayvarywithrespect to thesegrades,allsuchtiresmeetGeneral MotorsperformancestandardsandhavebeenapprovedforuseonGeneral Motorsvehicles. All passengertype (P Metric)tiresmustconform to Federal safetyrequirements in addition to thesegrades. Wheel Alignment and Tire Balance Thewheelsonyourvehiclewerealignedandbalancedcarefullyatthe factory to giveyou thelongesttire life andbestoverallperformance. to haveyourwheels alignedagain. In mostcases,youwillnotneed However, if you notice unusual tire wear or yourvehiclepullingonewayor to bereset. If younoticeyourvehicle theother,thealignmentmayneed to be vibrating whendrivingon a smoothroad,yourwheelsmayneed rebalanced. Wheel Replacement Replaceanywheelthatisbent,crackedorbadlyrusted. If wheel nutskeep comingloosethewheel,wheelbolts,andwheelnutsshouldbereplaced.If it (exceptsomealuminumwheels,whichcan thewheelleaksairout,replace GM dealer if anyofthese conditionsexist. sometimesberepaired).Seeyour Your dealer will know the kind of wheelyouneed. Eachnewwheelshouldhavethesameloadcarryingcapacitydiameter,width, offset,andbemountedthesame wayas theone it replaces. If youneed to replaceany of yourwheels,wheelbolts,orwheelnuts, replacethemonlywithnewGMoriginalequipmentparts.This way, youwill besureyouhavetherightwheel,wheelbolts,andwheelnutsforyour vehicle. 6-50