Symptom Chart

SYMPTOM	POSSIBLE CAUSES	ACTION
Crabbing	Incorrect rear thrust angle Front or rear suspension components	Check the rear alignment Check the front and rear suspension for signs of damage or wear
Drift/pull/wander	Tire pressures Uneven tire wear Damaged steering components Wheel alignment Brake drag Unevenly loaded or overloaded vehicle	Check and adjust the tire pressures (see visual inspection) Check for uneven tire wear, investigate the cause and rectify as necessary Check the steering for wear/damage Check and adjust the wheel alignment as necessary Check for binding brakes, rectify as necessary Advise the driver of the load issues
Front bottoming or riding low	Damaged suspension components Air spring fault	Check the suspension components for damage Check the dynamic suspension
Uneven tire wear	Incorrect tire pressure (rapid center rib or inner and outer edge wear) Incorrect front or rear toe (rapid inner or outer edge wear) Incorrect camber (rapid inner or outer edge wear) Tires out of balance (tires cupped or dished)	Check and adjust the tire pressures (see visual inspection) Check and adjust the wheel alignment as necessary Balance the wheels and tires as necessary
Harsh ride	Damaged suspension components Air spring fault	Check the suspension components for damage Check the dynamic suspension
Shimmy or wheel tramp	Wheels/tires Loose wheel nut(s) Loose front suspension fasteners Front wheel bearing(s) fault Worn or damaged suspension component bushing Loose, worn or damaged ball joint(s) Loose, worn or damaged steering components Front wheel alignment	Check the wheels and tires for condition and balance Check and tighten the wheel nuts and suspension fasteners to specification Check the front wheel bearings, suspension bushings, ball joints and steering components for wear or damage Check and adjust the wheel alignment as necessary
Poor return ability of the steering (self-centering)	Steering column Ball joints Steering components	Check the steering column universal joints, etc Check the ball joints and other steering components
Sway or roll	Loose front or rear stabilizer bar Worn lower suspension arm stabilizer bar insulators Air spring fault	Check the stabilizer bar security and condition Rectify as necessary Check the function of the active stabilization system (where installed) Check the air springs
Vehicle leans to one side	Front or rear suspension components Air spring fault	Check the front and rear suspension Check the air springs
Evidence of fluid on rear shock absorber	Fluid on shock absorber from an external source Fluid leaking from shock absorber	Shock absorber not faulty, do not renew GO to PINPOINT TEST A .