Wheel alignment is important to the health of your car or truck. If you hit a massive pothole, you might bump your suspension out of the carefully calculated locations in which the components have been set. All of the elements that make your car go straight are called “alignment.” The inclusive term “wheel alignment” involves three main measurements-caster( 主销后顷角), camber( 车轮外倾角), and toe( 前束) . T hese measurements have standards that a technician uses as targets of adjustment. In other words, get as close as you can to the right measurement. T he good news is that most modern cars only have adjustments for toe. Caster and camber went the way of the dodo thanks to the McPherson strut(麦弗逊支柱). Toe is a measurement of how much the front and/or rear wheels are turned in or out from a straight-ahead position. When the wheels are turned in, toe is positive. When the wheels are turned out, toe is negative. T he purpose of toe is to ensure that the wheels roll parallel. Toe also serves to offset the small deflections of the wheel support system that occur when the vehicle is rolling forward. Improper toe adjustment will cause premature tire wear and steering instability. If you are having trouble getting toe set on your car, some of the problem could be that the toe is changing. Often the tie rod stud will rotate and cause the toe to change. When you drive the car on the alignment rack after inspecting the vehicle and before making any changes, mark the tie outer and the inner drag link with chalk. Now you are ready to adjust toe to specification. Make sure the marked areas continue to line up. T hen tighten the bolts on the sleeve. T his will help you keep the correct toe setting on these vehicles.