Chevrolet 70 1969 Series, Руководство по ремонту

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SECTION 3
FRONT SUSPENSION
This group is divided into four sub-sections as shown in index below:
Section Page No.
3A Front End Alignment ................................................. 3A-1
3B Front A x l e .................................................................... 3B-5
3C Front S p r i n g s .............................................................. 3C-11
3D Front Hubs and Bearings ........................................... 3D-17
SECTION 3A
FRONT END ALIGNMENT
Proper alignment of front wheels must be
maintained to insure efficient steering and satis­
factory tire life. The most important factors of
front end alignment are wheel toe-in, wheel cam ­
ber, and axle caster. Front end alignment should
be checked at regular intervals, and particularly
after front axle has been subjected to heavy im ­
pacts such as a collision or a hard curb bump.
Before checking alignment, wheel bearings must be
properly adjusted since loose wheel bearings will
affect instrument readings when checking wheel
toe-in, wheel camber, and axle caster.
When checking alignment, instructions out­
lined in this section should be followed carefully,
as well as instructions covering related units such
as brakes, springs, steering gear, hubs and bear­
ings, and wheels and tires, which are given in
other sections of this manual. Front end alignment
chart (fig. 1) indicates points at which alignment
dimensions are taken.
The caster, camber, and toe-in dimensions
are for vehicle at design load (with frame level).
If frame is not level on alignment equipment, the
frame angle must be considered. This is espec­
ially important when making caster check for the
frame angle must be added to the caster angle to
obtain a true setting. All alignment checking should
be done with precision equipment and instruments.
DEFINITION OF TERMS
W H E E L TOE-IN
Distance front wheels are closer together at
front than at rear of axle (see "E "a n d " F , " fig. 1).
W H E E L C A M B E R
Amount wheels are inclined from vertical
plane (see " C ," fig. 1).
SERVICE DIAGNOSIS CHART
C O N D IT IO N
POSSIBLE CA U SE C O R R E C T IO N
Noisy Front End 1. Loose tie rod ends.
1. Replace ends.
2. Lack of proper lubrication. 2. Refer to LU BR ICATION (SEC. 0).
3. Broken spring leaf. 3. Replace spring leaf.
4. Loose U-bolts or spring clips.
4. Tighten.
Wheel Bounce 1. Unbalanced wheels or tires. 1. Refer to balancing (SEC. 10).
2. Unequal tire pressure.
2. See Load and Inflation Table (SEC. 10).
3. Weak or broken front spring. 3. Replace.
4. Excessive wheel or tire runout.
4. Refer to W H E E L S A N D TIRES (SEC. 10).
Excessive tire wear 1. Incorrect wheel alignment. 1. Align wheels (SEC. 3A).
2. Failure to rotate tires. 2. Refer to W H E E L S A N D TIRES (SEC. 10).
3. Improper tire inflation. 3. Refer to Load and Inflation Table (SEC .10)
4. Overloaded or improperly loaded. 4. Avoid overloading vehicle.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L