Gauging

Fig. 31 Installing rear thrust races & thrust bearing:

1. Assemble Compressing Fixture to Holding Fixture and retain in a suitable vise. Place front cylinder half in compressing fixture with flat side down, Fig. 31.
2. Use 4 zero thrust races and 3 zero shoe discs.
3. Install a zero thrust face, thrust bearing and a second zero thrust race on end of compressor shaft. Grease races and bearing with petrolatum.
4. Insert threaded end of shaft through needle bearing in front cylinder half, and allow thrust race and bearing to rest on hub of cylinder.
5. Install zero thrust race on rear end of compressor shaft so it rests on hub of swash plate. Then install thrust plate and a second zero thrust race, Fig. 31. Grease races and bearing with petrolatum.
6. Lubricate ball pockets on No. 1 piston with refrigeration oil and place a ball in each socket.

Fig. 32 Installing shoe disc:

7. Lubricate cavity of a zero shoe disc with refrigeration oil and place shoe disc over ball in front end of piston, Fig. 32. Front end of piston has an identifying notch in casting web. Piston rings should not be installed at this time. Shoe discs should not be installed on rear piston balls during this operation.
8. Rotate shaft and swash plate until high point of swash plate is over No. 1 piston cylinder bore.
9. Lift shaft assembly and hold front thrust race and bearing assembly against swash plate hub.

Fig. 33 Installing piston:

10. Position piston over No. 1 cylinder bore (notched end of piston on bottom and piston straddling swash plate) and lower shaft to allow piston to drop into bore, Fig. 33.
11. Repeat Steps 6 through 10 for pistons 2 and 3.
12. Install rear cylinder half on pistons, aligning cylinder with discharge cross-over tube hole in front cylinder. Tap into place using plastic mallet.
13. Position discharge cross-over tube holes between pair of compressing fixture bolts to permit access for feeler gauge, Fig. 33.
14. Install top plate on compressing fixture. Tighten nuts to 15 ft. lbs., using a 0-25 ft. lb. torque wrench.
15. Measure clearance between rear ball of No. 1 piston and swash plate as follows:
a. Select suitable combination of well-oiled feeler gauge leaves to fit snugly between ball and swash plate.
b. Attach spring scale reading 1-ounce increments to feeler gauge. Distributor point checking scale or spring scale may be used.

Fig. 34 Gauging rear piston ball:

c. Pull on spring scale to slide feeler gauge stock out from between ball and swash plate and note reading on spring scale as feeler gauge is removed, Fig. 34. Reading should be between 4 and 8 ounces.
d. If reading is under 4 or over 8 ounces, reduce or increase thickness of feeler gauge leaves and repeat Steps a through c until a reading of 4 to 8 ounces is obtained. Record clearance between ball and swash plate resulting in 4 to 8 ounce pull on spring scale.
16. Rotate shaft 120° and repeat Step 15 between same ball and swash plate. Record measurement.
17. Rotate shaft 120° and again repeat Step 15 between same parts and record measurement.

Fig. 35 Shoe disc size chart:

18. Select numbered shoe disc corresponding to minimum feeler gauge reading recorded in the 3 checks. Place shoe discs in parts dish or cups corresponding to piston No. 1 and rear ball pocket position for future reassembly. Shoe discs are provided in .0005 inch variations. As shown in Fig. 35, there are 11 sizes available for field servicing. All shoe discs are marked with the shoe size, which corresponds to the last 3 digits of the piece part number. Once proper selection of shoe has been made, matched combination of disc to rear ball and spherical cavity in piston must be kept in proper relationship during disassembly after gauging operation, and during final assembly of internal mechanism.
19. Repeat in detail same gauging operation for pistons 2 and 3.

Fig. 36 Gauging rear thrust races:

Fig. 37 Checking piston & shaft end play:

20. Mount dial indicator on edge of compressing fixture, Fig. 36. Adjust dial to zero. Push front end of shaft upward and record measurement. An alternate method of selecting proper race on compressors with Teflon piston rings is to use Gage Set J-9661-01, selecting a suitable feeler gauge leaf until result is a 4 to 8 ounce pull on scale between rear thrust bearing and upper (or outer rear) thrust race, Fig. 37. If pull is just under 4 ounces, add .0005 inch to thickness of feeler gauge used to measure clearance. If pull is just over 8 ounces, subtract .0005 inch from thickness of feeler gauge. Select a race 2 full sizes larger than feeler gauge thickness.

Fig. 38 Thrust races size chart:

21. On compressors without Teflon piston rings, select a thrust race with a number corresponding to amount of end play shown. On compressors with Teflon piston rings, select a thrust race with a number corresponding to 2 full sizes larger than dial indicator reading or feeler gauge measurement of endplay shown. Fifteen thrust races are provided in increments of .0005 inch thickness and one zero gauge thickness, providing a total of 16 sizes available for field service, Fig. 38. Thrust races are identified partly by their thickness in thousands in excess of thickness of zero thrust race. This number also corresponds to last 3 digits of piece part number. A tolerance of .0005 inch to .0015 inch is built into thrust races to provide a running clearance between hub surfaces of swash plate and front and rear hubs of cylinder.
22. Remove compressing fixture top plate.
23. Separate cylinder halves while unit is in fixture. It may be necessary to use a wood block and mallet.
24. Remove rear cylinder half and remove one piston at a time from swash plate and front cylinder half. Do not lose relationship of front ball and shoe disc and rear ball. Transfer each piston, ball and shoe disc into proper part dish or cup.
25. Remove rear outer zero thrust race from shaft and install thrust race previously selected.