TM 5-4310-360-14
(a) Reinstall crankshaft with pistons
6-2.
Pistons, Rings, Connecting Rods, Cylinder
and crankshaft attached, being
Block, Crankshaft and Crankcase continued.
careful not to damage oil feeder
ring (8, figure 6-2) when fitting
(2)
Piston cylinder. Check fit before
within lugs at bottom of crankcase
assembIing pistons to connecting rods.
(2) and being sure there are no
Piston without rings must slide
burrs or dirt on the pulley end of
through the cylinder of their own
the crankshaft that might cut the
weight and holding the skirt of the
oil seal (1). Replace oil feeder ring
piston with the two thumbs there
plate (30, figure 6-1).
should be no appreciable side motion
at any point of piston travel. Refer
(b) If oil seal (1, figure 6-2) is to be
to table 1-1 for allowable clearance.
replaced, slide on over crankshaft
and press into place in the crank-
(3)
Wrist pin piston. Wrist pins (7 and 20,
case, the lip or seal side toward
the crankcase. Do not hammer
soft hammer in piston bores at
directly on the seal.
ambient temperature. Be sure fibre
washers (8 and 21) at each end of the
(5)
Cylinder-crankcase. Coat bottom end
wrist pins (7 and 20) are in place
of cylinder bores (28, figure 6-1) and
before assembling to cylinder. Assem-
piston rings with oil and assemble
ble piston rings (5, 6, 7, 16, 17 and
cylinder over pistons. The bottom of
18) to pistons (6 and 19). Top two
the cylinder bores are chamferred and
rings are compression rings and dot
rings will compress into piston grooves
stamped on side of rings indicates top
by pressing cylinder downward and
of ring. Oil rings (7 and 18) cannot
twisting slightly from side to side.
be installed upside down as either
After cylinder is in place and before
position is correct.
cap screws (27) are tightened, rotate
crankshaft two or three times for
self-alignment. Tighten cap screws (27)
(4) Connecting rod crankshaft. Install
and torque to 18 foot-pounds. Install
bearing caps (10 and 23, figure 6-1)
key (7, figure 6-2) and flywheel
and secure with washers (12 and 25)
(5, figure 4-3) after cylinder head and
and screws (13 and 26). Tap cap
intercooler is assembled. Torque
Iightly to make sure bearing is making
flywheel bolt to 43 foot-pounds.
contact and tighten rod bolts. Torque
bolts to 8 foot pounds. The combined
(6)
Be sure crankcase is filled to proper
piston and connecting rod should turn
level with oil before operating or
on the crankshaft of their own weight
running in.
if bearing adjustment is correct. If
tight, cut paper shims and install
between cap and rod. If loose, file cap
6-3. Efficiency Test.
until fit IS sufficiently tight. Correct
clearance between connecting rod and
After compressor assembly is completely reas-
crankshaft journal is 0.0011 inch to
sembled and all connections are checked for leaks,
the compressor should pump up the air receiver
0.0019 inch (0.0028 cm to 0.0048
cm). Refer to table 1-1 for allowable
from 0 to 100 psi (0 to 7.03 kg/sq cm) in 22
wear clearance.
seconds.
Section II. ENGINE
6-4. General.
Refer to TM 5-2805-256-14/24P for repair instruc-
tions and parts lists for the engine.
6-4
