Chevrolet 70 1969 Series, Shop Manual

Page: 889 / 913

STEERING 9-13
CONTROL VALVE AND POWER STEERING GEAR OVERHAUL
There are four type 553-DV pow er steering gears (fig.
1) covered in the following overhaul procedures: The
m ajor differences in the gears is in the housings, size,
m ountings, direction of w orm shaft, adjustm ents, and
whether bearings or bushings are used in the housings.
R efer to “ Specifications” group at end of this section for
truck model application.
Illustrations shown in this part of the m anual are typi­
cal of all type gears unless otherwise specified. Overhaul
procedures are the sam e for all type gears except where
designated in the text.
Disassembly and assembly procedures m ust be per­
formed on a clean work bench. As in repairing any hy-
draulically operated unit, cleanliness is of the utm ost im ­
portance; therefore, the bench, tools, and parts m ust be
kept clean at all times. T horoughly clean the exterior of
steering gear with a suitable solvent, and when necessary
drain as m uch of the hydraulic fluid as possible from the
unit.
CLAMP YO KE REM OVAL
1. Drain as much fluid from the unit as possible.
2. If not previously removed, m ark the stub shaft and
clam p yoke before removing the yoke so they can be
assembled in the sam e position when the steering gear
is reassembled.
D O N O T H A M M E R O N T H E S H A F T A S T H IS
M A Y B R IN E L L T H E T H R U S T B E A R IN G S .
3. Rem ove clam p yoke bolt and remove yoke from the
stub shaft.
ADJUSTER PLUG ASSEMBLY
(Key Numbers in Text Refer to Figure 2)
REMOVAL
1. T urn stub shaft to turn P itm an shaft counterclockwise
until ball nut reaches end of travel at top.
2. Loosen the adjuster plug lock nut with a suitable
wrench. Rem ove the lock nut (fig. 22).
3. Using spanner wrench (J-7624), remove the adjuster
plug assembly (fig. 3).
DISASSEMBLY
1. W ith a screwdriver, remove upper thrust bearing re­
tainer (12) (fig. 4). Be careful not to score the needle
bearing bore. Discard retainer.
2. Remove upper thrust bearing spacer (II), thrust bear­
ing (9), and thrust bearing inner race (8) and outer
race (10).
3. Remove adjuster plug O-ring seal (7) and discard.
4. M ount adjuster plug in vise having brass jaws.
5. Remove stub shaft oil seal retaining ring (2) with
t r u -
arc pliers (fig. 5). Rem ove seal back-up washer (3).
6. Rem ove stub shaft oil seal (4) by prying out with a
screwdriver. Discard oil seal. N O T E : Use care to
avoid dam age to adjuster plug bore.
7. D o not rem ove stub shaft bearing (5) from adjuster
plug unless inspection shows necessity.
INSPECTION (Fig. 2)
1. Inspect thrust bearing spacer (11) for cracks or other
dam age.
2. Inspect thrust bearing races (8 and 10) for wear, pit­
ting, scoring, or cracks. If any of these conditions are
found, replace races.
3. Inspect stub shaft needle bearing (5) in adjuster plug
(6). If needles are broken or pitted, remove bearing
assembly by pressing from upper thrust bearing end
of plug, using rem over tool (J-6221) (fig. 6). Discard
the bearing.
ASSEMBLY (Fig. 2)
1. Position the adjuster plug on wood block.
2. If previously rem oved, install stub shaft needle bear­
ing (5) through thrust bearing end of adjuster plug.
Press against identification end of bearing, using in­
staller tool (J-6221) (fig. 6).
Bearing Retainer
Screwdriver
\ w \
Adjusting Plug tpm-<5310
F ig u re 3 — R e m o v in g A d ju s te r P lu g F ig u r e 4 — R e m o v in g T h ru st B e a r in g R e ta in e r
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L