Chevrolet 1977 10 Series, Repair Manual, Page: 49 / 468

STEERING 3B-7
center tooth space of the ball nut.
9. Pack the remaining portion of lubricant into the
housing.
10. Place the side cover gasket on the housing.
11. Install the side cover onto the pitm an shaft by
reaching through the side cover with a screwdriver and
turning the lash adjuster screw counterclockwise until the
screw bottoms; back the screw off one-half turn. Loosely
install a new locknut onto the adjuster screw.
12. Install and tighten the side cover bolts to
specifications.
CAUTION: I f new side cover bolts are used at
installation, be sure to use specified bolts which are
self locking.
Adjustm ent on Bench
1. Tighten the adjuster plug until all end play has been
removed and then loosen one-quarter turn.
2. Using an 11/16" 12-point socket and an in. lb. torque
wrench, carefully turn the wormshaft all the way to the right
turn stop and then turn back about one-half turn.
3. Tighten the adjuster plug until the proper thrust
bearing preload is obtained; (See the Specifications at the rear
of this M anual). Tighten the adjuster plug locknut to
specifications.
4. T urn the wormshaft from one stop all the way to the
other, counting the num ber of turns. Then turn the shaft back
exactly half the num ber of turns to the center position.
5. T urn the lash adjuster screw clockwise to remove all
lash between the ball nut and sector teeth. Tighten the
locknut.
6. Again using the 11/16" 12-point socket and an in. lb.
torque wrench, observe the highest reading while the gear is
turned through center position. See the Specifications Section
for proper over-center adjustment.
7. If necessary, readjust lash adjuster screw to obtain
proper torque. Tighten the locknut to 23 ft. lb. torque and
again check torque reading through center of travel.
POWER STEERING PUMP
INDEX
Overhaul O perations................................................................................ 3B-7
D isassem bly.............................................................................................. 3B-7
Inspection................................................................................................... 3B-7
A ssem bly.................................................................................................... 3B-8
OVERHAUL OPERATIONS
CAUTION: I f when overhauling a power steering
gear or pump, broken components or foreign
material are encountered, the remaining
components o f the entire hydraulic system should
be disassembled, inspected, thoroughly cleaned and
flushed before servicing is completed.
Disassembly (Fig. 3B-17)
Clean the outside of the pum p in a Nontoxic Solvent
before disassembly.
1. Remove pum p pulley by using tool J-25034 as shown
in Figure 3B-18.
2. Place the pump in a vise and remove the union and
"O" ring seal assembly.
CAUTION: In clamping pum p in vise, be careful
not to exert excessive force on the pum p front hub
as this may distort the shaft bushing.
3. Remove the pump reservoir retaining studs.
4. Remove the reservoir from the pum p housing by
tapping lightly on the outer edge of the reservoir with a soft
hammer. Remove the "O" ring seal from the pum p housing
and discard seal.
5. Remove magnet from housing assembly.
6. Remove the m ounting stud square ring seals and the
flow control valve square ring seal and discard.
7. On Corvette, remove filter and filter cage; discard
filter element.
8. Remove the end plate retaining ring. Compress the
end plate retaining ring by inserting a small punch in the 1/8"
diam eter hole in the pump housing. W hen the ring is in
compressed position, remove with a screw driver as shown
in Figure 3B-19.
9. Remove the end plate. The end plate is spring loaded
and will generally sit above the housing level. If sticking
should occur, a slight rocking action or light tapping with
a soft ham m er will free the plate. Remove the end plate
spring.
10. W ith the pum p still in a vise, remove the shaft
woodruff key and tap end of shaft gently with a soft ham m er
until the shaft pressure plate, pum p ring, rotor assembly and
thrust plate can be removed as a unit (fig. 3B-20).
11. Separate the parts removed in Step 9 above. If
inspection shows the shaft to be defective, separate it from
the rotor by removing the retainer snap ring. Discard the
snap ring.
12. Remove the end plate and pressure plate "O" rings
from the pum p housing and discard "O" rings.
13. Remove the dowel pins.
14. Remove the flow control valve and spring assembly.
15. Pry the shaft seal out of the pum p housing being
careful not to dam age the housing bore, discard the shaft seal.
Inspection
Clean all metal parts in a nontoxic solvent and inspect
as follows:
1. Flow control valve m ust slide freely in housing bore.
If sticking is observed, check for dirt and burrs.
2. Check cap screw in the end of the flow control valve
for looseness; if loose, tighten, being careful not to damage
machined surfaces.
3. Be sure th at pressure plate and pump plate surfaces
are flat and parallel with pum p ring. Check all of these parts
for cracks and scoring.
NOTE:
A high polish is always present on rotor pressure