Chevrolet DB90 Series, Service Manual

Page: 46 / 242

S ec. 4B -40
REAR SPRINGS AND SUSPENSION
or No. 2 lea f a re broken, the com plete spring a s ­
sem bly should be replaced.
3. Wash a ll g r e a se and dirt from shackle,
shackle pin or stud. Make su re lubricant p a ssa g e s
in pins a re clean. R eplace pins if e x c e s s iv e w ear
or other damage is evident.
4. Inspect spring eye bushing for w ear. If e x ­
c e s s iv e w ear is evident, p r e ss old bushings out
and p r e s s new bushings into p lace. R efer to "Speci­
fications" at end of this section for bushing s iz e s .
5. Replace rebound clip b olts, center bolt,
and U -b olts if distorted or damaged in any way.
REAR SPRING ASSEMBLY
1. Coat each spring leaf with a light film of
graphite g r e a se . Stack spring le a v es in c o rrect
ord er, then com p ress lea v es with C -clam p s or
arbor p r e s s . Install center bolt and nut and tighten
firm ly .
2. In stall rebound clip b olts and sp a c e r s.
Tighten b olts just enough to hold spring le a v e s in
alignm ent, but not enough to r e str ic t fr e e m ove­
ment of le a v e s. When clin ch er type rebound clip s
a r e used, bend c lip s into p lace.
REAR SPRING INSTALLATION
1. P osition spring sea t on axle, making su re
dowel is in place to properly lo ca te se a t. P osition
sp rin g on sea t, being su re center bolt en ters lo ­
cating hole in sea t. P la ce U -bolt sp acer on top of
sp rin g. Install spring U -b olts, at the sam e tim e
in stallin g radius rod bracket. Install nuts on U-
b olts and tighten firm ly.
IMPORTANT: U -bolt nuts m ust be retightened
w ith v eh icle loaded after installation is com pleted.
2. Connect spring e y e s to sh ack les a s p r e v i­
ou sly d irected under "Rear Spring Shackle Pin or
B rack et R eplacem ent."
3. L ubricate a ll shackle pins as directed in
LUBRICATION (SEC. 0).
4. In stall w h eels, then rem ove blocks from
under axle and fram e.
5. P la ce norm al load on v eh icle, then tighten
U -b olt nuts to torque liste d in "Specifications" at
end of this sectio n .
RADIUS RODS
DESCRIPTION
Cast I-b eam type radius rods have yoke type
en d s. Radius rods a re secu red to b rackets by pins,
with rubber bushings used between rod and pins
(fig. 7). P in s are secu red with nuts, w a sh ers, and
a r e locked to radius rod by draw keys in serted
through one sid e of each radius rod yoke, engaging
a flat on head of pin. Radius rod front bracket (eye)
is in tegral with rear spring front shackle bracket
(fig. 7). Radius rod rear bracket (eye) is a sep a r­
ate part, clam ped betw een lip on forw ard sid e of
spring sea t and lip on front end of U -bolt bottom
p late. T h ese radius rods require no lubrication.
REMOVAL AT FRONT END
1. R em ove nut, and w asher from radius rod
pin.
2. R em ove nut and from radius rod pin draw
key and drive draw key out of radius rod yoke.
3. R em ove pin from radius rod yoke and
bracket. R em ove rubber bushings from bracket.
REMOVAL AT REAR END
1. L oosen nuts on spring U -b o lts and back off
nearly to end of threads. D rive U -b olt bottom plate
down away from axle and let it r e s t on U -bolt nuts.
2. U sing a lead ham m er, strik e top of radius
bracket to dislodge bracket from betw een lip on
spring sea t and axle housing.
3. With radius rod and rea r bracket assem b ly
rem oved from v eh icle, disconnect radius rod from
rea r bracket a s previou sly d irected under "Re­
m oval at Front End.”
INSTALLATION AT REAR END
1. In stall new rubber bushings in radius rod
bracket, in sertin g one from each sid e . B ushings
may be coated with hydraulic brake fluid to fa c ili­
tate in stallation , but under no circu m sta n ces should
g r e a se or o il be applied to bushings.
2. P o sitio n radius rod bracket in radius rod
end yoke and in sert pin from outer sid e, aligning
fla t on head of pin with draw key hole in rod yoke.
3. In stall draw key in radius rod yoke, in sta ll
nut on key, and tighten fin ger-tigh t.
4. In stall w asher and nut on radius rod pin
and tighten firm ly . Tighten nut on radius rod pin
draw key.
5. P la c e radius rod and rear bracket under
v eh icle. P o sitio n upper edge of b racket between
lip on spring sea t and axle housing, driving it into
p la ce with a lead ham m er. R a ise bottom plate up
against axle housing, making su re low er edge of
radius rod bracket is in p la ce betw een lip on plate
and axle housing. Tighten spring U -b olt nuts, with
v eh icle under norm al load, to torque lis te d in
"Specifications" at end of this sectio n .
INSTALLATION AT FRONT END
To in sta ll radius rod at front end, accom p lish
ste p s 1 through 4 under "Installation at R ear End."
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT