Chevrolet 70 1969 Series, Руководство по ремонту

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STEERING 9-9
6. M ount steering gear housing in holding fixture or vise
so that top cover opening is up. Do not grip too tight­
ly.
7. Lubricate w orm thrust roller bearing and position in
cup in lower end of gear housing.
8. Place original pack of shims on top cover. Shim s are
available in 0.002. 0.005. 0.010 and 0.030 inch thick­
nesses. .A m inim um of three 0.002 inch and two
0.005 inch shims must be used for initial adjustm ent.
9. Lubricate upper w orm thrust bearing; then position
bearing on upper end of w orm shaft over cone. Place
top cover over shaft and on bearing.
10. Remove tape from w orm at both ends of the ball nut;
then gently rotate ball nut assem bly so that it con­
tacts stop pin in lower end of the worm .
11. Lift top cover, w orm , and ball nut assem bly by grasp­
ing top cover and worm . T urn the shaft into a vertical
position so that ball nut is on the bottom . Carefully
guide the assembly into gear housing until bearing
cone on w orm shaft contacts lower w orm thrust b ear­
ing. In so doing, rotate the w orm so ball nut return
guide clam p faces the back-up adjuster opening in the
housing. Bolt top cover to gear housing. Tighten bolts
to 35-45 foot-pounds torque.
12. A ccom plish all procedures steps 1 through 10 des-.
cribed under “ Installation of Pitm an Shaft and Side
C over” following:
INSTALLATION OF PITMAN SHAFT
AND SIDE COVER
All Steering Gears
1. W ith gear housing positioned in vise or holding
fixture so that w orm shaft is horizontal, proceed as
follows:
2. While holding w orm nut, turn w orm shaft to move
nut to center of worm . This is necessary so that worm
nut and Pitm an shaft will mesh properly when the
shaft is installed. C enter tooth on Pitm an shaft sector
m ust enter center space in w orm nut.
3. Apply proper lubricant to shaft bearing or bushing in
gear housing. Position shaft in gear housing, being
careful not to dam age bearings or bushings with ser­
rated end of the shaft.
4. Position a new gasket on gear housing side cover
opening.
5. Apply proper lubricant to side cover bearing or bush­
ing. Place side cover on lash adjuster screw in Pitm an
shaft. W ith screwdriver through hole in side cover,
thread lash adjuster screw through cover until cover is
pulled against housing. Back off lash adjuster screw a
few additional turns to provide backlash between sec­
tor gear on shaft and ball nut.
6. Install side cover to housing attaching bolts and lock
washers. Tighten bolts to 25-35 foot-pounds torque.
Install adjuster screw lock nut loosely.
7. Install new Pitm an shaft oil seal carefully over Pit­
m an shaft so that serrations on shaft do not dam age
seal. Lips of oil seal should face inside of gear hous­
ing. Be sure oil seal is well seated in housing. Tool
used to install bushing or bearing in housing m ay be
used to install oil seals.
8. On steering gears equipped with a back-up adjuster,
install back-up adjuster and lock nut loosely in the
gear housing. Do not m ake adjustm ent until all other
adjustm ents have been made.
9. Install the steering gear assem bly in the vehicle as di­
rected earlier.
10. Adjust worm bearings, and m ake Pitm an shaft lash
adjustm ent as previously described; then on steering
gears equipped with a back-up adjuster, tighten back­
up adjuster until adjuster bottom s against ball nut ret­
urn guide clamp. Back off adjuster 1/8 to 1/4 turn
and secure in place with adjuster lock nut. Purpose of
the back-up adjuster is to keep the worm shaft from
flexing up and down.
SPECIFICATIONS
M O D E L A PPLICA TIO N CHART
Truck Series Gear Model Ratio
Series 70-80 Conventional Cab M o d e l s ................................................................... 553-D-66 28.14 to 1
Series T M /8 0 ........................................................................................................... 568-D-46 30.51 to 1
Optional
Series 70-80 Conventional Cab M o d e l s ................................................................... 554-D-2 28.14 to 1
STEERING G EA R SPECIFICATIONS
M a k e .........................................................................Saginaw Steering Gear Division
T y p e .........................................................................Recirculating Ball and Sector Nut
Model ...................................................................... See Chart Above
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L