GMC 1990 Light Truck Repair Manual page 119

V FT H
6
A. Install Balls In This Hole While Slowly
Rotating Worm Counterclockwise
B Worm Flange
210. Screw
211. Clamp
212. Ball Guides
213. Balls
Figure 12—Installing the Balls into the Rack Piston
15. Stub shaft (251) from valve body (250) (figure 10).
• Hold the assembly and lightly tap the stub
shaft against the bench until the shaft cap is
free from the valve body.
• Pull the shaft assembly until the shaft cap
clears the valve body by about 6 mm (174-
inch).
• Valve spool (252) and seals (230) and (231)
(figure 11).
16. Screws (210), clamp (211) and ball guide (212).
• Balls (213).
CLEANING AND INSPECTION
p j f l Clean
• All parts with solvent and blow dry.
y | Inspect (Figure 1)
1. Pitman shaft and side cover.
— Bushing.
— Bushing surfaces in the side cover (225) for
scoring. Replace the side cover assembly if
necessary.
— Sealing and bearing surfaces of the pitman
shaft (221) for roughness, nicks, or other dam­
age. Replace the pitman shaft assembly if nec­
essary.
— Pitman shaft (221) for excessive wear or scor­
ing. Check the sector gear teeth for wear.
Replace the pitman shaft assembly if neces­
sary.
210
214 Rack pjston
B6517
POWER STEERING 3B3-5
— Adjuster screw (222) threads for wear. The
adjuster screw must be free to turn with no
end play.
2. Rack piston.
— Worm (248) and rack piston (214) grooves and
all balls (213) for scoring. BOTH MUST BE
REPLACED as a matched assembly.
— Seal (216) and ring (217) for wear.
— Ball return guide halves (212) for cracks and
damage.
— Bearing (247) and races (246) for scoring and
excessive wear.
— Rack piston (214) teeth and external ground
surfaces for scoring or excessive wear. If
either condition exists, replace the rack piston
(214) and worm (248).
3. Adjuster plug.
— Spacer (235) for wear or cracks.
— Races (236, 238) for wear or scoring.
— Adjuster plug (240) threads for wear.
— Bearing (237) for wear or scoring.
— Needle bearing (241) for wear, pitting or scor­
ing. Replace if necessary.
4. Valve and stub shaft.
— Seals (231) and rings (232).
— Shaft pin for wear or cracks. If excessively
worn or broken, replace the complete valve
and shaft assembly.
— Ground surface of the stub shaft (251). If a
crocus cloth cannot clean the nicks or burrs,
replace the entire valve assembly.
— Outside diameter of the valve spool and inside
diameter of the valve body (250). If a crocus
cloth cannot clean the nicks or burrs, replace
the entire shaft and valve assembly.
— The small notch in the skirt of the valve for
wear. If worn replace the complete valve
assembly.
— Valve spool inside the valve body (250). The
valve spool, when lubricated with steering flu­
id, must rotate freely without binding. If binding
occurs, replace the complete valve and shaft
assembly.
ASSEMBLY
B install or Connect (Figures 1, 4, and 10
through 14)
Tools Required:
J 4245 Snap Ring Pliers
J 6217 Valve Connector
J 21552 Ball Retainer
J 22407 Bearing Installer
J 8092 Bearing Driver
J 7079 Bearing Remover and Installer
J 8524-1 Driver
J 7624 Bearing Preload Spanner Wrench
1. Balls (213), alternately by color, in the rack piston
(214) (figure 12). Use J 21552 in the rack piston.
• Lubricate the 24 balls with power steering flu­
id.
2. Balls (213), alternating by color, in the ball guide
(212) (figure 13).