Due to the structural difference between independent suspension and non-independent suspension, the adjustment method is also completely different.
1. Toe adjustment of the front wheel
The toe adjustment is achieved by the length of the left and right tie rods. When adjusting, the steering wheel should be adjusted first, and the position of the steering wheel should be locked and fixed. After obtaining the correct toe value, the centering adjustment should also be carried out. The length difference between the left and right side tie rods should not be more than 3mm. If the lengths of the left and right tie rods are not equal, it will cause the steering angle to change. When adjusting the toe of an independent suspension car, you cannot use the method of jacking up the front axle to suspend the wheels, and can only push the wheels to rotate half a circle on the ground.
2. Adjustment of wheel camber, kingpin caster and kingpin inclination
For cars with independent suspension, if you want to increase the positive wheel camber angle, you need to move the upper angle out or move the lower ball hinge in. If you want to increase the positive caster angle, you need to move the upper ball hinge back or the lower ball angle forward. The relationship between kingpin inclination and wheel camber has been determined by the structure of the steering knuckle during vehicle design. Therefore, there is generally no need to specifically adjust the kingpin inclination angle. After the wheel camber angle is adjusted, the kingpin inclination angle is naturally correct.
Adjustment of positioning angle parameters For vehicles of different structures, the adjustment methods of positioning angles are also different, which is very different. The various adjustment methods are now summarized into the following 5 categories for description:
(1) Move the upper and lower swing arm adjustment method. This structure has a long hole in the bracket or the upper (lower) swing arm support. Loosen the fixing bolts and move the upper (lower) swing arm to change the camber angle of the vehicle. The adjustment of the wheel alignment of the Shanghai Santana sedan belongs to this kind. It is adjusted by moving in the long hole of the lower swing arm of the ball joint seat.
(2) Adjustment of strut-type independent suspension. There are 3 elongated holes on the upper support strut spring of the suspension strut. Loosen the fixing nut and use a socket wrench to move the suspension strut along the elongated hole to adjust the camber angle of the wheel. After adjustment, tighten the adjustment nut with a torque of 25N.m. Some vehicles have an inclined plane stop at the upper support. Loosen the fixing bolts, press down the inclined plane stop, and rotate a certain position to make the support rod slightly deviate from the center position to change the camber angle of the wheel.
(3) Support rod-cam adjustment method, support rod adjustment: shorten or increase the length of the support rod, you can change the caster angle of the kingpin. When the support rod is shortened, the lower swing arm is pulled forward to increase the caster angle, and vice versa, the caster angle decreases. The camber angle of the wheel is to use the lower swing arm to fix the inner end cam to move the lower swing arm in or out to change the camber angle of the vehicle.
(4) Increase or decrease gasket adjustment method. For spiral spring-type independent suspensions, adjusting shims are often installed at the junction of the upper swing arm shaft and the frame. If the gasket is moved from the front end to the back end, the caster angle of the kingpin can be increased, and if the thickness of the gasket is changed equally, the camber angle can be adjusted.
(5) Cam adjustment method. Some cars have 2 bushings at the inner end of the upper swing arm, 2 fixing bolts and cam assembly, which are installed on the frame fixing seat. Rotate the cam to change the camber angle and caster angle of the kingpin. If the two cams rotate in the same direction and the same amount, the upper swing arm can be moved in or out to change the camber angle. If you turn one cam or turn two cams in opposite directions, you can change the caster angle of the kingpin.
