GMC 1989 Light Duty Truck, Repair Manual, Page: 34 / 998

1B1 -16 A-6 AIR CONDITIONING COMPRESSOR
F -01600
F-01601
I. F ro n t th ru s t g ive s
th e p ro p e rc le a ra n c e .
J. C h e c k in g fo r sh o e
th ic k n e s s “ X ” .
Figure 35— C he cking th e P isto n and S h aft End Play
Figure 34— G aging th e Rear T h ru s t Plate
• From the bottom, apply full hand force at the
end of th e shaft a few tim es before reading the
c le ara n c e. T his will s q u e e z e the oil out from
betw een the m ating parts. Now push upward
and record the m e as u rem e n t. Dial indicator
increm ents are 0.03 mm (0.001-inch); estim ate
the reading to th e nearest 0.013 (0.0005-inch).
• An alternate m ethod is to use J 9661-01 in
selecting a su itab le fee le r g ag e leaf until the
result is a 1.1 N to 2 .2 N (4 to 8 o unces) pull on
th e scale b etw een th e rear thrust b earing and
u pp er (or outer rear) thrust race (figure 35).
If the pull is just less th an 1.1 N (4 o unces),
add 0.013 mm (0.00 05 -in ch ) to the thickness of
t h e f e e l e r s to c k u s e d to m e a s u r e th e
cle ara n c e. If th e pull on the scale reads just
over 2 .2 N (8 o un ces), then subtract 0.013 mm
(0.0005-in ch ) from the th ickn ess of the feeler
stock.
7. For eith er m ethod used, select a thrust race with a
“ n u m b e r” correspo n ding to T W O (2) F U L L S IZ E S
L A R G E R th an th e dial ind icato r or fe e le r g a g e
m e as u rem e n t of th e am ou n t of end play shown. (If
m e as u rem e n t is 0.18 m m (0.007-inch), select a No. 9
or 0 9 0 race).
Fifteen thrust races are provided in increm ents of
0.013 mm (0.00 05 -in ch ) thickness and one Z E R O
gage th ickn ess providing a total of 16 sizes. T h e
thrust race “ n u m b e r” corresponds to th e last th ree
digits of th e part num ber. R efer to figure 33.
8. R em o ve the nuts from th e top plate of th e J 9397.
9. R e m o ve the top plate.
10. S e p a ra te th e cylinder halves w hile th e unit is in the
fixture.
• If necessary, use a w ood block and a m allet.
11. R em o ve th e rear cylinder half; rem o ve o ne piston at
a tim e from the axial plate and front cylinder half.
• Do not lose th e relation sh ip of the front ball
and shoe disc and rear ball.
• Transfer each of th e piston, ball and shoe disc
sets to J 9 4 0 2 .
12. R em o ve th e rear outer “ z e ro ” thrust race (it will be
on top) from th e shaft and install th e thrust race just
selected in Steps 6 and 7 th at is in J 9 4 0 2 .
• T h e “ z e ro ” thrust race m a y be put aside for
re u s e in a d d itio n a l g a g in g o r re b u ild in g
operations.
PISTON RING REPLACEMENT
++
R e m o v e o r D is c o n n e c t (F ig u re s 1, 36 th ro u g h
39)
Tool R equ ired ;
J 2 4 6 0 8 Teflon Piston Ring Installer
Piston rings
(33)
and
(37).
• S lic e th ro u g h th e ring w ith a kn ife w h ile
holding the b la d e flat with th e piston surface.
• Do not d a m a g e the alu m in u m piston (32 ) or
piston groove.
C lean
C lea n the piston and piston ring grooves with a
re c o m m e n d e d c le a n in g so lven t (trich lo ro e th a n e ,
n aptha, S toddard solvent, kerosene, or eq u ivalen t)
and blow th e piston dry with dry air.
In s ta ll o r C o n n e c t (F ig u re s 1, 36 th ro u g h 39)
1. Piston (32) to J 2 4 6 0 8 -2 (figure 36).
• S et th e piston on a clean , flat su rface.
2. Piston ring (33 ) to J 2 4 6 0 8 -2 .
• P lace the dished or dull side down and the
glossy side up.
3. Piston ring (33) to piston (32) (figure 37).