Chevrolet 70 Series 1970, Service Manual

Page: 255 / 841

REAR SUSPENSION 4-42
INSTALLATION (REAR UNIT)
(R efer to F ig. 20)
1. P la c e spring assem bly on spring se a t, m ak­
ing su re ends of sp rin g assem bly a r e p ro p e rly
p ositioned and that ce n te r bolt e n te rs locating hole
in spring sea t.
2. In stall co m pression bolt through ro c k er
a r m b rack et and sp rin g eye.
3. R efe rrin g to ce n te r in set in fig u re 20, in­
s ta ll co m pression bolt, retaining bolt, co m pression
w asher, retain in g bolt flat w ash er and nut. Align
c e n te r tab s on o uter end of com p ressio n bolt with
lock bolt hole in b ra ck et, then in stall com pession
bolt lock bolt. Do not final tighten nuts and bolts
at th is tim e.
4. P osition rebound rubber r o lle r in ro c k e r
a r m , then in sta ll bolt and nut. Tighten nut to 100-
120 foot-pounds torque.
5. With sp a c e r on spring, in sta ll U -bolts.
6. In sta ll U -bolt anchor p late, U -bolt flat
w a sh e rs, and nuts. Tighten nuts to torque lis te d
in "T orque S pecifications" at end of th is section
under "Page and P age 800 Suspension S ystem ."
IMPORTANT: F inal tighten com pression bolt
retain in g bolt nut and com p ressio n bolt lock bolt
to torque liste d in "Torque Specifications" at end
of th is section, only a fte r the p ro p e r a x le -to -fra m e
alignm ent has been obtained.
7. Remove blocks and jacks fro m under the
fram e.
8. Check tandem alignm ent and adjust, if n ec­
e s s a ry , as d irec ted under "Tandem A lignm ent”
la te r in th is section.
9. F inish tightening co m pression bolt lock
bolt to p ro p e r torque.
ROCKER ARM
(PAGE AND PAGE 800)
ROCKER ARM REMOVAL (Item 4, Fig. 20)
1. To fa c ilita te rem oval of ro c k e r a rm , r a is e
front and r e a r ax les, safely support underneath
and rem ove w heels.
2. Remove c o tte r pin, cap stud nut, cap stud
th ru st w asher, and cap stud backing w a sh ers from
com pressio n cap and stud assem bly.
3. Remove co m p ressio n c a p -to -fra m e b ra c k e t
bolt and lock w asher.
4. Remove com p ressio n cap and stud a s s e m ­
bly fro m ro c k e r a rm and fra m e .
5. At each end of ro c k e r a rm , rem ove r e ­
bound bolt, nut, and rebound r o lle r fro m sprin g
holder b rack et.
6. R aise fra m e until ro c k e r a rm end b ra c k e ts
c le a r ends of front and r e a r sp rin g s. Support
fra m e sec u rely .
7. Rem ove ro c k e r a rm by pulling stra ig h t off
hanger pivot pin.
CLEANING, INSPECTION, AND REPAIR
1. Inspect ro c k e r a rm . If broken o r cracked,
re p la c e ro c k e r a rm .
2 .
Inspect com pression cap and stud a s s e m ­
bly. If crack ed o r broken, re p la c e cap assem bly.
3. Inspect ro c k e r a rm ru b b er bushings. If
bushings a r e w orn o r d e te rio ra te d , re p la c e .
4 .
Inspect ro c k e r a rm stop
(2 6 ,
fig.
20)
a t­
tached to fra m e . If broken o r crack ed , re p la ce.
ROCKER ARM INSTALLATION
(Item
4 ,
Fig. 20)
1. P o sitio n ro c k e r a rm with ru b b e r bushings
in p lace on fra m e b ra ck et,
2 .
P osition co m pression cap and stud a s s e m ­
bly through ro c k e r a r m and fram e b ra c k e t.
3. In stall co m pression cap and stud to fram e
b ra c k e t lock w ash er and bolt. Do not tighten bolt
a t th is tim e.
4 .
In stall backing w a sh e rs, th ru st w a sh e r, and
cap stud nut. Tighten nut firm ly , then in sta ll co tter
pin.
5 .
Now tighten co m p ressio n cap and stud to
fram e b ra c k e t bolt to torque liste d in "T orque
S p ecification s” at end of th is section.
6. Low er fra m e and ro c k e r a rm until ends of
fro nt and r e a r sp rin g s r e s t against cam s of ro c k er
a rm sp rin g ho ld er b ra c k e ts.
7. In stall rebound b olts, nuts, and rebound
r o lle r s to ro c k e r a rm sp ring holder b ra c k e ts.
Tighten nuts to
1 0 0 -1 2 0
foot-pounds to rq u e.
8. R eplace w heels a t fro n t and r e a r axles as
d irec ted in WHEELS AND TIRES (SEC.
10)
in this
m anual.
9. Rem ove su pp o rts from axles and fra m e and
safely low er to no rm al position. Inspect com pleted
job fo r po ssib le defects.
TORQUE RODS (FRONT UNIT)
(PAGE AND PAGE 800)
REMOVAL (Fig. 20)
The p ro c ed u re fo r rem oving the torque rods
is as follows:
1. Remove c o tte r pins, nuts, co m p ressio n
w a sh e r, and b r a s s w ash er fro m both ends of torque
rod.
2 .
D rive com p ressio n b o lts with c o lla rs out
of sp rin g fra m e hanger at fron t and axle sp ring
se a t at r e a r with a soft ham m er.
INSPECTION
1. In spect to rq ue ro d s fo r c ra c k s , bent con­
dition, o r dam aged th re a d s. R eplace with new p a rt
if dam aged in any way.
2 .
Inspect ru b b e r bushings fo r d eterio ratio n .
R eplace if n e c e ssa ry .
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL