(8) Remove the piston rings (10, 11, and 12)
from the piston.
(9) Remove and disassemble the five
remaining piston and connecting rod
assemblies.
b. Cleaning and Inspect n.
io
(1) Clean all parts in an approved cleaning
solvent; dry with clean, dry, compressed
air.
(2) Inspect pistons, piston pins, bearings, and
connecting rods for cracks, distortion,
scoring, pitting, or other defects.
(3) Replace piston rings and damaged or
defective parts.
c. Repair and Assembly.
(1) Check piston fit using a piece of 0.005-
inch feeler stock cut inch wide. Dress
Figure 67. Checking oil pump end clearance.
the edges of the feeler stock with a stone
to remove burs and feathered edges. The
e. Installation (fig. 59).
block and pistons must be at room
(1) Position the assembled oil pump on the
temperature when piston fit is tested.
center bearing cap; secure with the nut
Position the feeler stock midway between
(24) and lockwasher (23).
the piston pin bosses. With the piston
(2) Install the oil pan (para 117
c).
and feeler stock inserted about 2 inches
(3) Install the engine (para 114
c).
into the block, the feeler stock must pull
119. Pistons and Connecting Rods
from the block with 5 to 10 pounds pull. If
a. Removal and Disassembly (fig. 68).
the feeler stock does not offer enough
(1) Remove the engine (para 114).
b
resistance, perform the same test with a
(2) Remove the cylinder head (pa 115a).
new standard size piston. If sufficient
(3) Remove the oil pan (para 117).
a
resistance still is not obtained, rebore the
(4) Ream the ridge of the top of each cylinder
cylinders (pare 122) and install oversize
d
bore with a standard ridge reamer. Blow
pistons.
metal fragments from the cylinder with
(2) If new pistons (13, fig. 68) and pistonns
ip
compressed air.
(14) are being used, press a new sleeve
(5) Remove the two cotter pins (33) and nuts
bearing (16) into each connecting rod
(32) that secure a connecting rod cap (17)
(17). Ream and hone the sleeve bearings
to a connecting rod; remove the cap and
to 1.1097- to 1.1095-inch diameter.
sleeve bearing (19).
(3) If the pistons and pins are not being
(6) Push the assembled piston (13) and con
-
replaced, check the clearance between
necting rod up through the top of the
the piston pins and the sleeve bearings.
block.
Clearance must be between 0.0002 and
Caution
0.0006 inch. If clearance is not within this
W hile pushing the piston and rod
tolerance, press new sleeve bearings into
from the block, be very careful the
the connecting rods and ream and hone to
connecting rod does not scratch
provide the proper clearance.
After
the cylinder wall.
honing, 75 percent of the sleeve bearing
(7) Remove the two retaining rings (15) from
surface must contact the piston pin.
the piston; push the piston pin (14) from
(4) W hen pins, bushings, and pistons of the
the piston and rod.
proper size have been found, assemble
Note
the pistons to the connecting rods as
Disassemble the pistons and piston
follows:
rods in sets and keep the sets
(a) Heat the pistons and connecting
together. Also, be sure each
rods in an oven or in water to a
piston and piston rod set is
minimum of 160 F.
reinstalled in the cylinder from
which it was removed.
TAGO 6358-A
78