Symptom Chart

SYMPTOM	POSSIBLE CAUSES	ACTION
Tires show excess wear on edge of treads	Tires under-inflated Vehicle overloaded	Correct pressure to specification Correct as necessary
Tires show excess wear on edge of treads (having the correct tire pressures)	Incorrect toe setting	Set to specification
Tires show excess wear in centre of tread	Tires over-inflated	Set pressure to correct specification
Other excessive tire wear problems	Incorrect tire pressure Incorrect tire and wheel usage Loose or leaking air springs Geometry out of alignment Loose, worn or damaged suspension components Wheel and tire assembly out of balance Excessive lateral or radial runout of wheel or tire	Set pressure to correct specification Install correct tire and wheel combination Tighten or install new air springs as necessary Check and adjust geometry to specification Inspect, repair or install new suspension components as necessary Balance wheel and tire assembly Check, repair or install a new wheel or tire as necessary Check, repair or install a new wheel or tire as necessary
Wheel mounting is difficult	Incorrect application or mismatched parts, including wheel studs and wheel nuts. Corroded, worn or damaged components	Clean or install new components as necessary
Wobble or shimmy affecting wheel runout	Damaged wheel (eventually damaging wheel bearings and causing uneven tire wear)	Inspect wheel rims for damage and runout. Install a new wheel rim as necessary
Excessive vibration, rough steering or severe tire wear	Loose or incorrect installation of components	Tighten or install new components as necessary
Vehicle vibrations	Tires and wheels mismatched Inflation pressure too high or too low Uneven tire wear Out-of-balance wheel, tire, wheel hub or disc assembly Damaged or distorted wheel from road impact hazard or incorrect handling Excessive radial runout Excessive lateral runout Incorrectly seated tire Loose wheel mountings - damaged wheel studs, wheel nuts, worn or broken wheel hub face or foreign material on mounting faces Defective wheel bearings Brake disc imbalance Water in tires Loose engine or transmission mounts Incorrect front end alignment Loose or worn driveline or suspension parts Excessive driveshaft runout or imbalance Worn or damaged flexible drive joint	Install correct tire and wheel combination Set pressure to correct specification Refer to tire wear information in this Symptom Chart Determine the out-of-balance component and balance or install a new component as necessary Install a new wheel as necessary Check for incorrect wheel and tire specifications. Install a new wheel or tire as necessary Install a new wheel or tire as necessary Re-mount the tire as necessary Clean mounting surfaces. Tighten or install new components as necessary Install a new bearing set as necessary Refer to the relevant Diagnosis and Testing article in the repair information. REFER to: BRAKE SYSTEM Remove water Tighten or install a new mount as necessary Complete front end alignment procedures as required Repair or install new driveline or suspension components as necessary Balance or install new driveshaft as necessary Install new flexible drive joint as necessary
Damaged wheel hub stud threads	Sliding wheel across the wheel studs during installation Loose wheel nuts	Install new wheel studs as necessary
Broken wheel studs	Loose or overtightened wheel nuts	Install new wheel studs as necessary
Corrosion and contamination streaks from the wheel hub wheel stud holes	Loose wheel nuts	Check complete assembly. Install new components as necessary. Follow correct torque procedure
Damaged wheel nuts	Loose wheel assembly Over-tightened wheel nuts	Install new wheel nuts as necessary. Follow correct torque procedure
Frozen wheel nuts	Corrosion or galling	CAUTION: Do not permit lubricant to contaminate wheel hub stud holes or wheel nut seats If corrosion is light, wire brush away corrosion. If corrosion is excessive install new wheel studs and wheel nuts as necessary