Chevrolet 1973 Overhaul Manual page 16

W o b b le Plate
No. 1 Piston
Front
Cylinder
H alf y
| Com pressing |
Fixture J-9397
Fig. 21--lnstaliing Piston, Front Ball and Seat and
Rear Ball
provided in .0005" variations including a basic ZERO
seat.
The second gauging operation, performed at the rear
shaft thrust bearing and race pack, is designed to obtain
.0005" to .0015" preload between the hub surfaces of the
wobble plate and the front and rear hubs of the cylinder.
A total of 14 steel thrust races, including a basic ZERO
race, are provided in increments of .0005" thickness to
provide the required fit. Proper selection of thrust races
and ball seats is of extreme importance.
1. Secure from service parts stock:
Four-ZERO thrust races
Three-ZERO ball seats
Two-New thrust bearings
2. Assemble a ZERO thrust race, a new needle thrust
bearing and another ZERO thrust race, in that
order, to the front end of the shaft (A dab of clean
petroleum jelly will hold the bearing-race pack
together and in place on the shaft). Lubricate front
and rear faces of the wobble plate with clean
refrigeration oil.
3. With the front half of the cylinder assembly resting
on Tool J-9397, insert the shaft threaded end
through the front main bearing until the thrust race
assembly rests on the front cylinder hub.
4. Assemble a ZERO thrust race, a new needle
bearing and a second ZERO thrust race in that
order, to the rear of the shaft.
5. Apply a light smear of clean petroleum jelly to the
ball pockets of each of the three pistons.
6. Place the balls in the piston pockets. The petroleum
jelly will hold the balls in place.
7. Apply a light smear of petroleum jelly to the cavity
Front Thrust Races
3 and Bearing M B
H olding Fixture
H J-9396 H P
8. Rotate the shaft and wobble plate until the high
9. Repeat this operation with pistons No. 2 and No. 3.
10. Align the rear head casting with bores, suction
11. Place the cylinder assembly in the checking cage
12. Use a leaf type feeler gauge and a suitable spring
AIR C O N D IT IO N IN G COM PRESSOR
Fig. 22--Assem bling C ylinder Halves
of three new ZERO ball seats and place one seat
over each front piston ball. There should now be a
ball and seat in the front ball pocket of each piston
and a ball only in the rear ball pocket.
NOTE: Do not assemble any of the piston
rings at this time.
point of the wobble plate is directly over the
cylinder bore previously designated as No. 1. Lift
up slightly on the shaft and wobble plate assembly,
insert the front (notched) end of the No. 1 piston
into the cylinder bore, and at the same time, place
the front ball and seat and the rear ball only over
the wobble plate (fig. 21). Hold front thrust bearing
pack tight against wobble plate hub while lifting
shaft.
passage, discharge crossover holes, and dowel pins.
Tap into place, using a plastic block and mallet (fig.
22
).
with the front of the compressor shaft pointing up,
positioning the discharge tube opening between the
cage bolts. This will provide access for the feeler
gauge. Assemble the cage and tighten all nuts
evenly to 14-16 ft. lbs. torque.
scale to check clearance between the REAR ball
and the wobble plate (fig. 23) of the No. 1 piston.
Use a suitable combination of feeler gauge leaves
until 4 to 8 oz. of force is required to pull gauge
from between the ball and the plate.
NOTE: Use undamaged feeler gauges gener­
ously lubricated with clean refrigeration oil.
Support the spring scale so that only the
1-11
OVERHAUL MANUAL