Chevrolet 10 Series 1970 Service Manual page 510

STEERING 9-2
F i g . 1 — R e m o v i n g P i t m a n A r m ( T y p i c a l )
J - 21143 fo r 40, 50 and 60 S eries.
S e ries T ru cks, rem ove steerin g connecting rod fro m
pitm an arm .
2. Disconnect horn w ire
horn button cap fro m center of steerin g wheel.
3. Loosen the pitman shaft lash adjuster s c re w locknut
and turn the adjuster s c re w a few turns in a counter­
clockw ise d irectio n (fig . 2).
im posed on the w orm b earings by the close meshing
of rack and s e cto r teeth.
wheel gently fro m one stop all the way to the other,
ca refu lly counting the total number of turns.
turn wheel back exactly half way, to center position.
CA U TIO N :
Do not turn
against stops when steerin g re la y rod is d is-
connected as dam age to b all guides may result.
4. Using an Inch Pound Torqu e W rench and socket on
steerin g wheel nut, m easure torque requ ired to keep
the wheel in motion.
lim its given in S pecifications Section, w orm bearing
p reload adjustment is necessary.
5. T o adjust w orm b earin gs, loosen w orm bearin g ad­
ju ster locknut and turn w orm bearing adjuster shown
in F igu re 2 until th ere is no p ercep tib le end play in
w orm . Check torque at steerin g wheel, readjusting
if n ecessary to obtain p rop er torque.
nut and recheck torque.
a fte r adjustment of w orm b earin gs, there is probably
dam age in the b earin gs due to s e v e re im pact o r to
im p ro p er adjustment and the gea r must be d isa s­
sem bled fo r replacem ent of damaged parts.
6. A fte r p rop er adjustment of worm is obtained, and all
mounting bolts secu rely tightened, adjust lash ad­
ju ster screw . F ir s t turn the steerin g wheel gently
fro m one stop all the way to the other, ca refu lly
counting the total number of turns.
back exactly half way, to center position.
adjuster s crew clock w ise to take out a ll lash in gea r
teeth, and tighten locknut.
w heel, taking highest reading as wheel is turned
through center position.
T O O L —J -5 5 0 4
T O O L —J - 6 6 3 2
On 40, 50 and 60
at m ast jacket and rem ove
This rem oves the load
F ir s t turn the steerin g
Then
steerin g wheel hard
If torque does not lie within
Tighten lock-
If the gea r fe e ls "lu m p y"
Then turn wheel
Turn lash
Check torque at steerin g
See Specifications fo r
F i g . 2 — S t e e r i n g G e a r A d j u s t m e n t Po in ts ( T y p i c a l )
p ro p er secto r lash adjustment.
sa ry to obtain p ro p er torque.
NOTE: If maximum specification is exceeded,
turn lash adjuster s cre w cou n ter-clock w ise, then
com e up on adjustment by turning the adjuster in
a clockw ise motion.
7. Tighten locknut then recheck torque as it must lie
between specified lim its.
8. On 10, 20 and 30 S eries trucks rea ssem b le pitman
arm to se cto r shaft, lining up m arks made on d is­
assem bly. Torqu e nut to sp ecification s.
and 60 S eries trucks assem ble steerin g connecting
rod to pitman arm .
CA U TIO N :
If a clamp type pitman arm is used,
spread the pitman arm
wedge, to slip the arm onto the pitman shaft.
not spread the clamp m ore than requ ired to slip
o v e r pitman shaft with hand p ressu re.
ham m er the pitman arm onto the pitman shaft o r
dam age to the gea r may result.
in stall the hardened steel washer b e fo re install--
ing the nut.
NOTE:
The pitman arm to pitman shaft and
connecting rod fasten ers a re im portant attach­
ing parts in that they could a ffec t the p e r fo r ­
mance o f vita l components and system s, and/or
could resu lt in m ajor rep a ir expense. They must
be replaced with one o f the same part number
o r with an equivalent p art if replacem en t b e­
com es n ecessa ry. Do not use a replacem ent
p art o f le s s e r quality
Torqu e values must be used as sp ecified during
rea ssem b ly to assure p ro p er retention o f this
part.
9. Install horn cap o r ornam ent and connect horn w ire
at chassis connector.
Steering G ear High Point C entering—C -P l 0 -2 0 -3 0
1. Set fron t wheels in straight ahead position.
be checked by d rivin g ve h icle a short distance on a
Readjust if n eces­
On 40, 50
just enough, with a
Do
Do not
Be sure to
o r substitute design.
T h is can
CHEVROLET TRUCK SERVICE MANUAL