P-9-TM-457-35
T. O. 35 C2-3-442-2
TM-07464A-35
TM 5-6115-457-34
e, To measure clearance and gap for
CAUTION
each piston ring (10, 11, and 12), insert a
piston (13) in cylinder bore in the inverted
Do not use broken piston rings or
position. Insert each piston ring, one at a
carbon scrapers on ring lands
time, about two inches down in the cylinder
since this practice can result in
bore and bring the bottom edge of the piston
cutting sides of grooves. Be sure
(13) up against the ring to square the ring
bottom of each ring groove is
in the cylinder bore. Check gap with a
clean and oil return holes in oil
feeler gauge. If gap clearance for any ring
ring groove are open.
is not as specified in table 1-1, the ring
must be filed or honed to specification, or
b. If pistons have carbon on them, soak
replaced.
pistons in cold water overnight and then let
them dry (preferably in sunlight). Most of
the carbon can then be removed with a
8 - 2 1 7 . REPAIR.
hardwood stick.
a. When installing a new bearing (8)
8-216. INSPECTION.
into the connecting rod, the joint on the
diameter of the bearing must be at right
a. Refer to table 1-1 and inspect parts
angles (90 10 degrees, either left or right)
of the vertical centerline of the connecting
for dimensional tolerances. Replace defec-
tive parts.
rod. After pressing new bearing in place
machine accurately to dimensions in table
1-1.
b. Inspect piston for burned condition,
cracks, distortion, galling, or any other
b. Connecting rod bearings (3) should
defects. Replace defective piston.
always be replaced as a set (two halves
make a set). If inspection of one bearing
c. Inspect piston pins and rod bearings
shell indicates minimum thickness, then
for scoring, galling, distortion, or cracks.
replace all six connecting rod bearing
Replace defective bearings.
shells.
d. Inspect connecting rod for cracks,
8-218. REASSEMBLY.
breaks, or distortion. Replace defective
connecting rod.
Refer to figure 8-62 and reassem-
ble connecting rods and pistons group in
NOTE
the reverse order of index numbers
Bent rods should be discarded. D O
assigned. Pay particular attention to the
not attempt to align rods by bending.
following:
Abrasive materials may roll around
between bearings (8) and crankshaft
a. Reassemble rod (7) on piston (13) so
journals causing scratches in the
that the etched cylinder number on rod (7)
bearing without actually becoming
is on the same side as the "V" mark in the
embedded in the aluminum. Such
piston (13).
scratches are not necessarily harm-
ful and do not indicate that bearings
b. Use a suitable piston ring expander
(8, figure 8-62) should be replaced.
to install piston rings (10, 11, and 12) on
8-131
