Steering and vibration concerns are not always the result of improper alignment. Tire lead is a condition caused by worn or improperly-manufactured tires. Tire lead is the vehicle deviation from a straight path on a level road without pressure on the steering wheel. In order to determine if the vehicle has a tire lead problem, refer to Radial Tire Lead/Pull Correction in Suspension General Diagnosis.
Before making any adjustment that will affect the tire and wheel alignment, verify correct alignment readings and alignment adjustments:
| • | Inspect all tires for proper inflation pressures. Also verify that all the tires have nearly even tread wear. |
| • | Inspect the control arm ball studs. If the studs are loose, correct them before adjusting the tire and wheel alignment. Refer to Ball Stud Check in Front Suspension. |
| • | Inspect the tie rod ends. If the ends are loose, correct them before adjusting the tire and wheel alignment. Refer to Steering Gear Replacement in Power Steering. |
| • | Check the tires and wheels for runout. |
| • | Inspect the vehicle trim height. If the height is out of limits and a correction is to be made, make the correction before adjusting the alignment. Refer to Trim Height Specifications in General Diagnosis. |
| • | Inspect the steering gear for looseness at the frame. |
| • | Inspect the control arms for loose bushings. |
| • | Inspect the stabilizer shaft for loose or missing parts. |
| • | Inspect the shock absorber and the springs for improper operation. |
| • | Inspect the suspension and the steering components for damage. Replace the parts as necessary. |
| • | Inspect the vehicle for stability. The fuel tank should be full, or the vehicle should have compensating ballast. |
| • | Jounce the vehicle lightly 3 times in the rear and 3 times in the front. |
Give consideration to excess loads, such as tool boxes or sample cases, which are normally carried in the vehicle. These loads should remain in the vehicle during alignment adjustments.
Give consideration also to the condition of the equipment being used in order to adjust the alignment. Follow the equipment manufacturer's instructions. Regardless of the equipment used, the vehicle must be on a level surface, both front-to-rear and side-to-side.
