Chevrolet 70 1969 Series, Shop Manual

Page: 124 / 913

SECTION 3B
FRONT AXLE
FRONT SUSPENSION 3B-5
Reference is made to axle models in this sec­
tion. Refer to "Specifications" at end of this sec­
tion for axle model. For truck series application,
refer to front of manual.
Axle steering knuckles are constructed as
shown in figures 2 and 3. Wheel bearings, springs,
steering, and brake parts which are mounted on
front axle are described in their respective section
in this manual. Specifications and pertinent front
axle service information is given in "Specifications"
at end of this section.
FRONT AXLE CONSTRUCTION
Front axle center section is one-piece steel
forging with I-beam section in which dowel pins
are installed to locate spring seats. Outer ends of
axle center are machined to accommodate steer­
ing knuckles and king pins.
FRONT AXLE GENERAL
MAINTENANCE
Following maintenance operations should be
performed at intervals determined by severity of
service:
1. Inspect spring U-bolts for tightness. If
loose, tighten as directed in " F R O N T SPRINGS"
(SEC. 3C) later in this group.
2. Tighten steering arm and tie rod end stud
nuts to torque specified in S T E E R IN G S Y S T E M
(SEC. 9) of this manual.
3. Lubricate front axle parts as instructed in
LU B R IC A T IO N (SEC. 0) of this manual. When lub­
ricating front axle parts, observe condition of seals
at tie rod ends. If seals are found to be damaged
or missing, new seals should be installed im med­
iately. Refer to S T E E R IN G S Y S T E M (SEC. 9) of
this manual.
4. Examine steering knuckle bearing caps for
tightness and evidence of lubricant leakage. Tighten
or replace parts as required.
5. On F-070 axle, inspect and tighten king
pin draw key nuts. Loose draw keys will permit
king pin to turn in axle center, thus enlarging king
pin hole. If hole becomes too greatly enlarged,
replacement of axle center may be necessary. If
draw key holes become enlarged beyond use of
new key, replace axle center. IT IS N O T SA F E
T O R E A M A N D BUSH D R A W K E Y H O L E S .
6. Inspect king pin and steering knuckle bush­
ings for wear.
7. Check up and down movement of knuckles on
king pins. Excessive movement will pound and
damage the thrust bearings. Refer to "Specifica­
tions" for maximum axle to knuckle clearance.
8. Check stop screws and adjust when neces­
sary.
9. When steering difficulty or abnormal tire
wear is indicated, check front end alignment as
previously instructed under " F R O N T E N D A L IG N ­
M E N T " (SEC. 3A).
STOP SCREWS
Adjustable stop screws are located between
each steering knuckle and axle center to prevent
wheels from contacting chassis on extreme right
and left turns. The stop screws are installed in the
steering knuckles and stop against the axle center
as shown in figure 1 on F-070, F-090, F-110 and
F-120 axles. On F-150 and F-160 axles, stop
screws are installed on axle center and stop pads
are on steering knuckle.
Steering gears are equipped with built-in stops
in steering gear assembly to prevent steering
mechanism from bottoming at extreme turns. Stop
screws are therefore set to obtain the maximum
turning angles provided in these models.
1. Pitman arm must be installed correctly on
A — Dimension varies with different size tires. Set stop
screws to provide % " clearance between tires
and chassis at extreme turn positions.
t p m
-76
Figure 1 — Steering Knuckle Stop
Screw Adjustment Typical
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L