Chevrolet 10 Series 1970, Service Manual

Page: 152 / 671

FRONT SUSPENSION 3-4
F ig . 3 —S top Screw A d ju stm e n t
A ll except School Bus and
Flat Face Cowl M o d e ls —38-1/2° ± 1/2° both sides
School Bus and
F lat Face Cowl M o d els—44-1/2° ± 1/2° both sides
If a fter adjustment tir e s have less than 5/8” clearance
fro m any ch assis obstruction, turn stop screw s to obtain
this clearan ce.
FRONT END A LIG N M E N T
C o r r e c t alignm ent o f the fron t suspension must be
maintained to insure e ffic ie n t steerin g and sa tisfa cto ry
tir e life . Check alignm ent at regu lar in terva ls and p a r ­
tic u la rly a fte r fron t suspension has been subjected to
ex tre m e ly heavy s e r v ic e o r s e v e r e im pact loads.
B e fo re checking and adjusting alignm ent, such com po­
nents as wheel bearin gs, sprin g height, tie rods, steerin g
gear, kingpin bushings, shock ab sorbers and tir e inflation
should be inspected and c o rre c te d w here n ecessary.
Caster and C am b er—-Figure 4
P o s itiv e ca ster is the amount in d eg rees o f the back­
ward tilt o f the kingpin. P o s itiv e cam ber is the amount
in d e g re e s that the fron t w heels are tilted outward at the
top fro m a v e r tic a l position. Both angle adjustments are
n ecessa ry fo r steerin g sta b ility and safe veh icle handling.
Coil Spring M odels
On 10-30 S e ries c o il spring m odels, c a ster and cam ber
adjustments are made by means o f shims located between
the upper control arm shaft and the mounting bracket a t­
tached to the suspension cro ssm em b er.
A s e r ie s o f concave and convex spacers with fla t oppo­
site sides a re used. These sp h erica l spacers allow a
p ositive c ro s s -s h a ft-to -b ra c k e t attachment re g a rd less of
the number of caster/cam b er shims used.
M easure 10-30 S e rie s c a ster and cam ber as follow s
(r e fe r to F igu re 5):
Caster
1. Using a bubble p ro tra to r m easure fra m e angle " B ”
at location shown in F igu re 5.
2. Check c a ster angle on alignm ent machine.
3. Add angle “ B ” and c a ster angle to determ ine fram e
c o rre c te d angle.
4. M easure dim ension
“ A.” .
5. Using dim ension “ A ” and the c a s te r-c a m b e r chart
(fig . 6) fo r the appropriate veh icle, shown below, find
the recom m ended ca ster angle.
6. The fra m e c o rre c te d angle, Step 3 above, should c o r ­
respond to the recom m ended angle on the chart with­
in ± 1/2°. Make changes as n ecessa ry to bring
ca ster angle within lim its.
C am ber
1. D eterm ine v e h i c l e cam ber angle on alignm ent
machine.
2. M easure dim ension “ A
3. Using dim ension
“ A ” and the c a s te r-c a m b e r chart
F ig . 4 —F ro n t End A lig n m e n t
CHEVROLET TRUCK SERVICE MANUAL