2. Wheel alignment is characterized by four parameters (see Figure 36.2):
Figure 36.2. Angles determining wheel alignment: 1. Camber angle, 2. Wheel toe-in, 3. Kingpin caster angle, 4. Kingpin transverse caster angle.
Camber angle is the angle at which the front wheels deviate from the vertical when viewed from the front of the vehicle. a "positive" camber angle is one in which the tops of the wheels diverge.
Wheel toe is the distance between the front sides of the inner edges of the wheels (measured at the height of the hub) differs from the diametrically opposite distance measured between the rear sides of the inner edges of the wheels.
The kingpin inclination angle is the angle between the kingpin axis and the vertical when viewed from the side of the vehicle. A kingpin inclination angle that is "positive" is one in which the kingpin axis is tilted backwards at the top.
The transverse inclination angle of the kingpin is the angle (when viewed from the front of the car) between the vertical and the imaginary line passing through the upper mount of the guide tube and the ball joint of the lower suspension arm (or through the kingpin bushings).
3. With the exception of wheel alignment, all other angles are set during manufacturing and cannot be adjusted in any way. Therefore, it can be assumed that if the car has not been in an accident, all pre-set angles will be correct. If there is any doubt about their accuracy, you should contact your Ford dealer, since the nominal angle values vary greatly between models and also depend on the equipment installed on the vehicle; in addition, special sensors are required to check these angles.
4. There are two methods available to a mechanic to check wheel alignment. One method is to use a gauge to measure the distance between the front and rear inner edges of the wheels. Another method involves examining the track left by the vehicle on a special surface that records any deviation of the tire from straight-line movement. Relatively inexpensive equipment for performing both types of alignment checks at home can be purchased from specialized auto stores.
5. If the alignment check performed by one of these methods reveals the need for adjustment, carry it out as follows in accordance with the type of steering gear.
Cars with a "gear-rack" steering mechanism
6. Turn the steering wheel all the way to the left and record the number of protruding threads on the right tie rod. Now turn the steering wheel all the way to the right and record the number of protruding threads on the left side. If the numbers match, subsequent adjustments will be made equally on both sides. If there are more thread turns protruding on one side than on the other, it is necessary to compensate for the difference during the adjustment process.
It is extremely important that after adjustment the number of protruding threads on both sides must match.
7. To adjust the wheel alignment, loosen the locknut securing the ball joint to the tie rod and turn the tie rod with a self-locking wrench until the desired setting is achieved. If you look from the side of the car, turning the tie rod clockwise will increase the toe-in, and turning it counterclockwise will decrease the toe-in. Each time you turn the tie rods a quarter turn, recheck the toe-in using one of two methods.
8. After adjustment, tighten the lock nuts and install the rubber steering gear boots.
Cars with "screw-nut" steering mechanism
9. Loosen the nuts of the clamp bolts securing the ball joint to the end of the tie rod and turn the tie rod with a self-locking wrench until the desired setting is achieved. The ends of the tie rod have left and right threads, so turning the tie rod one way increases the length, and turning the other way decreases the length of the tie rod. At the same time, increasing the length of the transverse steering rod reduces the toe-in; decreasing the length increases the toe-in. Each time you turn the tie rod a little, recheck the toe-in.
10. After completing the adjustment, tighten the tie rod ball joint clamp bolt nuts.
[The original article is posted at: www.fordbook.ru]