GMC 1990 Light Truck Repair Manual page 122

3B3-8 POWER STEERING
wrench near vertical while turning the wrench
to the left at an even rate (figure 19). If the
reading is less than 0.45 N-m (4 in. lbs.) or
more than 1.15 N-m (10 in. lbs.), repeat the
adjustment procedure.
• Lubricate the stub shaft (251) area outside the
dust seal (206) with chassis lubricant or an all
purpose grease.
2. Rack piston (214) using J 21552 (figure 4).
3. Bearing (209) using J 22407 and J 8092.
4. Washers (207) and seal (254)using J6219 (figure
1
).
5. Retaining ring (205).
6. Dust seal (253).
7. Gasket (224).
8. Pitman shaft (221), side cover (225), nut (227)
assembly.
9. Bolt (226).
\J & \ Adjust (Figure 21)
Tool Required:
J 7754-01 Torque Wrench
Pitman shaft preload (figure 21).
1. Attach tool J 7754-01 and a 12-point socket on
the stub shaft splines.
2. Center the steering gear by turning the stub
shaft (251) from right to left and counting the
number of turns. Turn the shaft back halfway
to the center position.
3. Check the combined ball and bearing preload
by turning the torque wrench through the cen­
ter of travel. Note the highest reading.
4. Tighten the adjusting screw (222) until the
torque wrench reads 0.6 - 1.2 N-m (6-10 in.
lbs.) higher than the reading noted in step " 3."
• The total reading should not exceed 2.25
N-m (20 in. lbs.) torque.
Tighten
• Nut (227) to 27 N-m (20 ft.lbs.).
5. Re-check the preload after tightening the nut
(227).
10. Plug (215), seal (216), ring (217), and seal (218).
11. Plug (219) and retaining ring (220) (figure 22).
SAGINAW INTEGRAL
POWER STEERING
GEAR—CK (GMT 400)
NOTICE: Repair the steering gear in a clean,
dust-free location, using clean tools and equip­
ment. Dirt or grit will damage the machined
surfaces and result in leakage or damage to
the steering gear assembly.
If broken components or foreign materials are found
during disassembly of the gear the hydraulic system
should be disassembled, inspected, cleaned and
flushed before servicing is complete.
Service information is shown in figures 23,24, 25, 26,
and 27.
The ball nut and control rings (seals) generally need
not be replaced unless cut or damaged. If cut or dam­
aged, inspect all mating parts for burrs, cracks,
scratches, or damage. Replace or repair as needed.
In some instances, " power steering fluid" will be
specified to lubricate parts upon assembly. In these
cases, GM Power Steering Fluid, part no. 1050017 or
equivalent should be used. DO NOT use brake fluid,
automatic transmission fluid, or other non-approved flu­
ids.
SAGINAW POWER
STEERING P U M P -
MODEL TC
NOTICE: Repair the pump only In a clean, dust-
free location, using clean tools and equipment.
Dirt or grit will damage the machined surfaces
and result in leakage or damage to the pump.
If broken components or foreign materials are found
during disassembly of the pump, the hydraulic system
should be disassembled, inspected, cleaned and
flushed before servicing is complete.
Before beginning disassembly of the pump, remove
the reservoir filler cap (when used) and drain the oil
from the reservoir by filler cap (when used). Drain the
oil from the reservoir by inverting the pump so oil may
drain out the filler hole. After the oil is drained from the
reservoir, replace the cap.
DISASSEMBLY
Clean
Exterior of the pump with solvent.
Remove or Disconnect (Figures 28 through 39)
— Clamp the front hub of the pump in a soft jawed
vise.
1. Clips (26), if equipped.
• Pry the tab and slide the retaining clip off (fig­
ure 29).
2. Reservoir (24) (figure 30) or return tube (15) (figure
39) depending on the model.
3. O-ring (25).
4. Fitting (23) (figure 31).
5. O-ring seal (22).
6. Flow control valve (21).
7. Flow control spring (20).
8. Retaining ring (19) (figure 32).
• Use suitable snap ring pliers.
9. Driveshaft (17).
10. Bearing (18) (figure 33).
11. Driveshaft seal (16).
• Pry the seal loose with a flat head screwdriver
(figure 34).
12. Retaining ring (14).
• Insert a punch into the access hole and pry the
ring loose (figure 35).
13. Thrust plate (13) (figure 36).
• Use a 16 mm (5/8-inch) piece of bar stock or
suitable brass drift.