Chevrolet 70 Series 1970, Service Manual

Page: 193 / 841

FRONT SUSPENSION 3-10
A—Dimension varies with different size tires. Set stop
screws to provide Vs" clearance between tires
and chassis at extreme turn positions.
TPM-7608
Figure 5—Typical Steering Knuckle
B ushings are held in p lace at upper end by the
king pin nut and sp a cer (
6
). V ertical thrust is taken
by a r o lle r -ty p e thrust bearing (11). Thrust m ove­
ment is held to a m inim um by the u se of spacing
w a sh ers (7) betw een upper knuckle yoke and axle
cen ter end. Upper end of knuckle pins a re se a le d
with dust caps and g a sk ets, retained in p la ce with
s c r e w s . Low er end of knuckle on F -090 and F -120
a x le s (in set, fig .
2
), are se a led with an inverted
expansion plug held in p la ce with a lock ring. On
F -1 6 0 a x le s a retaining ring is in stalled on low er
end of king pin (fig.
2
) to retain king pin bushing.
Right and left ste erin g arm s a re keyed to knuckles,
and retained in p la ce with nuts and cotter p in s.
STEERING KNUCKLE
REMOVAL (F ig. 2)
If d esired , ste e r in g knuckles may be rem oved
from front axle without rem oving front axle a s ­
sem b ly from the v e h icle . To rem ove ste erin g
knuckles from the axle eith er with or without r e ­
moving the front axle a ssem b ly from the v e h ic le ,
p roceed a s follow s:
1. R em ove hubs, b earin gs, and brake m echan­
ism . D isconnect tie rod and drag link from a rm s.
2. R em ove cap s c r e w s which attach dust cap
and gasket to knuckle.
3. On F -090 and F -1 2 0 a x les (in set, fig . 2),
rem ove the low er expansion plug lock ring and
plug. On F -160 a x le s (fig. 2), a king pin bushing
retaining ring is lo ca ted at low er end of king pin.
The purpose of this ring is to keep steerin g knuckle
low er bushing in p la c e . Do not rem ove ring u n less
ring is broken or damaged.
4 . R em ove co tter pin, king pin nut, and ste e l
sp a c e r (
6
). U sing su itab le b r a ss d rift, drive the
kingpin downward out of axle and knuckle. R em ove
knuckle, thrust bearing (
1 1
), and spacing w asher
(7) from the a x le . S leev e bushing (2) can now be
rem oved.
STEERING KNUCKLE
INSTALLATION (F ig. 2)
The im portance of c le a n lin e ss when a s s e m ­
bling ste e r in g knuckle p arts cannot be o v e r s t r e s s ­
ed. If king pins and bushings a re in sta lled with
p a r tic le s of dirt or m etal betw een bearing su r ­
fa c e s, e x c e s s iv e w ear w ill r e su lt, n ecessita tin g
p rem ature rep lacem en t of p a r ts.
1. R efer to "Inspection and Repair" fo r in­
sp ection and rep air p ro ced u res.
2. P o sitio n knuckle to axle center; then slid e
thrust bearing a sse m b ly betw een low er fa ce of axle
cen ter and steerin g knuckle low er yoke. Make c e r ­
tain the retain er is on top of bearing with lip of
retain er down. Align king pin h oles in knuckle yoke
with king pin hole in a x le cen ter.
3. With a x le cen ter held rig id ly , p la ce a jack
under knuckle yoke, then r a is e knuckle su fficien tly
to take up a ll c lea ra n ce betw een low er yoke, thrust
b earin g, and lo w er fa c e of axle cen ter end.
4. Check cle a ra n ce betw een top fa ce of axle
cen ter end and fa ce of knuckle yoke. S e lect sh im s
o r spacing w asher (7) of c o r r e ct s iz e to provide
thrust clea ra n ce lis te d in "Specifications" at end
of th is se c tio n . T h ese are availab le in different
th ic k n e sse s.
5. Make certain king pin hole in axle cen ter,
the king pin, and nut a r e clean and dry. King pin nut
should thread on king pin fr e e ly without bind.
6
. In sert king pin through bottom yoke of
knuckle; then drive pin into p la ce w ith lead ham­
m er. P la c e king pin s le e v e bushing (2) over king
pin, then p r e s s into p la c e . B e su re s le e v e bushing
is in sta lled flu sh with pin. Install s t e e l sp a c er (
6
)
on top of bushing.
7. Make su r e th read s on king pin and nut are
clean and dry; then in sta ll king pin nut. Tighten nut
to m inim um torque sp e c ifie d in "Specifications";
then tighten nut until next s lo t on nut lin e s up with
cotter pin hole through kingpin. Install new cotter
pin, full s iz e of hole.
8
. On F -090 and F -1 2 0 a x le s (in set, fig . 2),
in sta ll new in verted expansion plug in lo w er h ole.
Install plug lock ring, seatin g ring se c u r e ly in
groove.
9. On F -160 a x le s, if low er bushing retaining
ring (9) is bent or damaged, rep lace ring.
10. In stall new kingpin dust cap gasket (5) at
top; then in sta ll dust cap (3). Tighten sc r e w s firm ly .
11. Connect tie rod and drag link to steerin g
a r m s. Install brake m echanism and hubs. Check
front end alignm ent fa cto rs and stop sc r e w settin g .
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL