368 Auto Suspension and Steering Copyright by Goodheart-Willcox Co., Inc. Possible Cause Out of balance Lack of rotation Worn steering or suspension components Loose wheel bearings Out of balance Excessive runout Worn steering or suspension components Loose wheel bearings Underinflation Lack of rotation Excessive camber roll due to high caster setting High-speed cornering Overinflation (Bias-type tires) Lack of rotation Excessive toe angle (Bias tire) Excessive camber angle Excessive toe angle (Radial tires) Out of spec. turning angle (Toe-out on turns) Scalloped wear Random cupping Shoulder wear Center tread wear Feather edge wear (Scuffing) Uneven wear (One side of tread) Symptom Perfect Equipment Corp. Figure 17-12. Abnormal tire wear. Note the symptom and possible causes. These are just a few problems. There are others, such as cuts, bulges, tread separation, etc. Check tires carefully.