Jeep UNIVERSAL CJ-2A - Page 36

'Jeep' UNIVERSAL and 'Jeep' DISPATCHER
D
FIG. 39·-CHECKING PISTON AND
CONNECTING ROD ALIGNMENT
1-Feeler Gauge
2-Fixture
piston pin lock screw and torque 35 to 41 lb-ft.
[4,8 a 5,7 kg-m.].
d. Place piston and rod assembly in a connecting
rod aligning fixture and check alignment of the
assembly as shown in Fig. 39. Follow instructions
furnished with the fixture.
e. Using a feeler gauge and new piston rings, check
the width of the two companion ring grooves and
the oil ring groove. Replace the piston if the widths
of the grooves are not within the limits given in the
specifications.
FIG. 40-CHECKING PISTON RING
SIDE CLEARANCE
1-Feeler Gauge
2-Piston Ring
Insert feeler gauge between ring and piston to back
of groove. Replace piston if ring grooves are not
within allowable tolerances. If a feeler gauge larger
FIG. 41--PISTON RING GAP
than .006" [0,152 mm.] can be inserted hi;" [1,6
mm.]
between piston and upper compression ring,
groove is worn excessively bell-mouthed and
piston should be replaced.
f. Check piston ring end gap by placing compres-
sion ring in cylinder bore below ring travel using
head of an inverted piston as a plunger to push
ring in squarely. End gap must be as shown in
Par. D-34 for all rings. If less, file ends to obtain
minimum gap. With cylinders bored to an exact
ring oversize of +.020", +.030", or +.040" [0,508-
0,762-1,016 mm.] the proper end clearance as in-
dicated in Par. D-34 will result. If end gaps are not
within the limits given, rings are of the wrong size
or were incorrectly filed for fitting.
g. Install a new ring set using either production
replacement rings or service type oil control rings.
Production type replacement piston rings are the
same as the original factory-installed rings while
service oil control ring sets have different com-
ponents, notably the oil ring expander. Follow
instructions of manufacturer for proper installation.
Use a piston ring expander to install rings on
pistons. Do not expand rings more than necessary
to install, alsq be careful not to burr the piston
with ends of rings. Install bottom (oil) ring first,
center ring second, and top ring last.
The width of the compression rings is %2" -[2,38
II}m.] and that of the oil control ring is %" [4,78
nim.]. While the compression rings are of the same
size, they are different in construction and must
not be interchanged. Install these rings as shown
in Fig. 42. The upper compression ring has an
inside beveled edge which must be installed toward
the piston top. The face of the lower compression
ring is tapered approximately .001" [0,03 mni.].
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