GMC 1976 ZEO 6083 Maintenance Manual page 106

Figure 79-Gaging Rear Piston Ball
d. If reading in Step c. above is under 4 OR
over 8 ounces, reduce or increase thickness of Feeler
Gage leaves and repeat Steps 1 . through c. above
until a reading of 4 to 8 ounces is obtained . Record
clearance between ball and axial plate that results in
the 4 to 8-ounce pull on Spring Scale .
16 . Now rotate shaft 120° and repeat Step 15
between same ball and axial plate. Record this meas-
urement. If shaft is hard to rotate, install shaft nut
onto shaft and turn shaft with wrench .
17 . Rotate shaft another 120° and again repeat
Step 15 between these same parts and record meas-
urements .
Figure 80-Available Service Shoes and Thrust Races
AIR CONDITIONING SYSTEM 1- 89
Figure 81-Selection of Proper Shoe Disc
18 . Select a "numbered" shoe disc corresponding
to minimize feeler gage reading recorded in the three
checks above. (See example in figure 81) . Place shoe
discs in Parts Tray J-9402 compartment correspond-
ing to Piston No . 1 and rear ball pocket position .
Shoe discs are provided in .0005" (one-half thou-
sandths) variations . There are a total of 11 sizes
available for field servicing. All shoe discs are
marked with the shoe size, which corresponds to the
last three digits of the piece part number . (See Shoe
Disc size Chart in figure 80 above) .
Once a proper selection of the shoe has been made, THE
MATCHED COMBINATION OF SHOE DISC TO REAR BALL
AND SPHERICAL CAVITY IN PISTON MUST BE KEPT IN
PROPER RELATIONSHIP during disassembly after gaging
operation, and during final assembly of internal mechanism .
19 . Repeat in detail the same gaging procedure
outlined in Steps 15 through 18 for Piston No . 2 and
No . 3 .
20 . Mount Dial Indicator J-8001-3 on edge of
Compressing Fixture J-9397 with Clamp J-8001-1
and Sleeve J-8001-2 (figure 81). Position Dial Indica-
tor on rear end of shaft and adjust to "zero" .
Figure 82-Gaging Rear Thrust Race
POSITION POSITION
POSITION
SELECT
AND USE
1 2
3
SHOE NO .
PISTON NO . 1 .019" .0195"
.019"
19
PISTON NO . 2 .020"
.020" .020"
20
PISTON NO . 3
.021" .021"
.022" 21
SHOE DISC THRUST BEARING RACE
Min .
( Part
Dial
Part No . Identi- Feeler No . Identi- Indi-
Ending fication Gage Ending fication cator
In Stamp Reading In Stamp Reading
000 0 .0000 000 0 .0000
175 17-1/2 .0175 050 5 .0050
180 18 .0180 055 5-1/2 .0055
185 18-1/2 .0185 060 6 .0060
190 19 .0190 065 6-1/2 .0065
195 19-1/2 .0195 070
7
.0070
200 20 .0200
075 7-1/2 .0075
205 20-1/2 .0205 080 8 .0080
210 21 .0210
085 8-1/2 .0085
215 21-1/2 .0215 090 9 .0090
220
22
.0220 095 9-1/2 .0095
100 10 .0100
105 10-1/2 .0105
110 11 .0110
115 11-1/2 .0115
120
12 .0120