To adjust toe-in, change the lengths of the tie rod connecting the steering knuckle arms. 1. In the type in which the tie rod is behind the spindles, increasing the tie rod length increases toe-in. In the type where the tie rod is in front of the spindles, increasing the tie rod length increases toe-out. 2. In the double tie rod type, toe-in adjustment is carried out with the lengths of the left and right tie rod kept identical. If the lengths of the left and right tie rods are different, even correct toe-in adjustment will bring about incorrect turning angle adjustment.
Camber and Caster
Click on the bulb mark or the underlined sentence. The adjustment methods for camber and caster depend on the model. Below are typical methods. Since the toe-in changes if the camber and/or caster are adjusted, the toe-in must always be checked after the camber and/or caster adjustment.
1. Separate camber adjustment On some models, the steering knuckle bolts can be replaced with camber adjusting bolts. Camber bolts have a smaller shank diameter allowing camber adjustment. This type of adjustment is used on strut type suspensions.
2. Separate caster adjustment The caster is adjusted by changing the distance “L” between the lower arm and strut bar by using the nut or spacer of the strut bar. This type of adjustment is used on strut type or double wishbone type suspension, in which the strut bar is located in front of or behind the lower arm.
3. Simultaneous camber and caster adjustment
(1) The eccentric cam type mounting bolt is at the inside end of the lower arm. Turning this bolt moves the center of the lower ball joint to incline and adjusts both the camber and caster. This adjustment method is used on strut type or double wishbone type suspensions.
(2) Turning the eccentric cam type mounting bolts at the front and rear of the lower arm changes the installation angle of the lower arm and changes the position of the lower ball joint. This adjustment method is used on strut type or double wishbone type suspensions.
(3) The upper arm mounting angle, that is, the upper ball joint position, is changed by increasing or decreasing the number and/or thickness of the shims. This adjustment method is used on double wishbone type suspensions.
Example of Camber and Caster
The following is an example of adjusting the Supra JZA80 (1998). (For details, refer to the Repair Manual.)
(1)Measure the camber and caster.
(2) As shown in the chart, read the distance from the marked point to 0 point.
(3) Adjust the front and/or rear adjusting cams according to the values read from the chart.
Turning Radius (Wheel Angle, Turning
The type with a knuckle stopper bolt can be adjusted, but the type without this bolt cannot be adjusted.
In the case of rack-and-pinion steering gear, the wheel angle is typically determined by the point at which the steering rack end makes contact with the steering rack housing. Consequently, there is usually no knuckle bolt. If the lengths of the left and right tie rod ends are different,
Rear Wheel Alignment
Rear wheel alignment of an independent rear suspension is accomplished by adjusting the camber and toe angle. The method of adjusting the camber and toe angle differs depending on the type of suspension. Some models have no mechanism for adjusting the camber.