GMC 1982 Light Duty Truck Service Manual page 281

POWER STEERING GEAR (800 MODEL)
G E N E R A L D E S C R IP T IO N
These Integral Power Steering Gears
have a control valve which directs oil
to either side of the rack piston. The
rack piston converts hydraulic power
into mechanical force. This force is
transmitted to the mating pitman
shaft teeth, through the pitman shaft
to the steering linkage.
The model 800 incorporates a
recirculating ball system in which
steel balls act as a rolling thread
between a steering worm-shaft and
the rack-piston.
P«r*
K t y M§. Mama
1 -H O U S IN G , STEERING GEAR
2 -R A C E , THRUST BEARING (W O R M )
3 -B E A R IN G ASSY , ROLLER THRUST (W O R M )
4 -R A C E , THRUST BEARING (W O R M !
5 - W O R M , STEERING
6 -S E A L , " O " R IN G (STUB SHAFT)
7 - SHAFT, STUB
8 -S P O O L , VALVE
9 -S E A L , " O " RING (SPOOL)
10 - BODY, VALVE
I I - RING , VALVE BODY (3)
1 2 -S E A L , " O ' RING (VALVE BO D Y) (3)
1 3 -R E T A IN E R . BEARING (ADJUSTER)
1 4 -S P A C E R , THRUST BEARING
1 5 -R A C E , UPPER THRUST BEARING (SMALL)
1 6 - B E A R IN G , UPPER THRUST
1 7 -R A C E , UPPER THRUST B EA RING (LARGE)
1 8 - SEAL, " O " RING (ADJUSTER)
(H >
®
' 3 '- ®
(»}— ^
(31)-------
g > - -----to
K ly Ha Part Name
19 - P LU G , A D JU S T E R
2 0 - B E A R IN G , NEEDLE
21 - SEAL, STUB SH AFT
2 2 - SEAL, STUB S H A F T D UST
2 3 - R IN G , R E T A IN IN G
2 4 N U T , A D JU S T E R P LU G LO C K
2 5 - B E A R IN G A S S Y NEEDLE (P IT M A N
2 6 - SEAL, P IT M A N S H A F T (S IN G LE
2 7 - W A S H E R , SEAL B A C K -U P (P IT M A N
2 8 - S E A L , P IT M A N S H A F T (D O U B LE LIP)
2 9 - W A S H E R SEAL B A C K -U P (P IT M A N
3 0 - R I N G R E T A IN IN G ( P IT M A N
31 - W A S H E R P IT M A N S H A F T LO C K
3 2 - N U T , P IT M A N S H A F T
3 3 - N U T , R A C K P IS T O N
3 4 - BALL
3 5 - G U I D E , BA LL R ETU R N (2)
3 6 - C L A M P B A LL R E T U R N G U ID E
...
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P O W E R S T E E R IN G G E A R E X P L O D E D V IE W
(Model 800)
Fig. 3B 3-56-O verhaul 8 0 0 /8 0 8 G ear, C hart A
POWER STEERING SYSTEM 3B3-25
Repair procedures for these two
models are different. Note the side
cover differences in the sketch
below.
Whenever a part which
forms a sealing surface for an 1 O "
ring is removed, the " O" ring seal
should also be removed and
replaced with a new seal. W hen­
ever one of the Pitman shaft or
stub shaft seals are removed all
adjacent seals should be removed
and replaced with new seals.
Lubricate all new seals with
power steering fluid to ease assembly.
R ectangular side cover held in
place with four bolts
(800 MODEL)
Key No ta r t Nome
37 SC R EW A S S Y
PLU G R A C K
38
39 SEAL O '
4 0 R IN G R A C K
41
SEAL O
42 P LUG H O U S IN G
S H A F T ) 4 3 R IN G R E T A IN IN G
4 4
LIP) G E A R A S S Y
S H A F T ) 4 5 SEAL A S S Y
4 6
C O V E R A SS Y
4 /
S H A FT) BO LT, H E X
S H A FT SEAL) 4 8 N U T LA S H
4 9
S P R IN G
50 POPPET
51
C O N N E C T O R
52
C O N N E C T O R
(a) < s>
L O C K W A S H E R & (?)
P IS T O N
R IN G (R A C K P IS T O N )
P IS T O N
R IN G ( H O U S IN G E N D P L U G )
E N D
( H O U S IN G E N D P L U G l
P IT M A N S H A FT
G A S K E T
H O U S IN G SIDE
H E A D I SIDE C O V E R ) (4 )
AD JU STER
C H EC K V A L V E
C H EC K V A L V E
IN V E R T E D FLARE
IN V E R T E D FLARE
k
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