Figure 3-50. Piston and connecting rod assembly, removal and installation.

NOTE

piston to the crankshaft. The rod is drilled to

Move the piston to the bottom of its travel and place a

provide lubrication to the piston pin at the upper

cloth on top of the piston to collect the cuttings.

end and is equipped with an oil spray nozzle for

cooling the underside of the piston head. The angle

(5) After the ridge is removed, turn the

of the ports in the cylinder liners creates a uniform

crankshaft until the piston is at the top of its stroke

swirling motion to the intake air as it enters the

and carefully remove the cloth with the cuttings.

cylinder. T h i s m o t i o n p e r s i s t s t h r o u g h o u t t h e

(6) After the ridge is removed, turn the

compression stroke and facilitate scavenging and

crankshaft until the piston is at the top of its stroke

combustion.

and carefully remove the cloth with the cuttings.

b. Removal.

(7) Remove the bearing cap and lower bearing

(1) Drain oil and remove engine oil (para 3-

shell from the lower end of the connecting rod; then

24).

push the piston and rod assembly out through the

( 2 ) Remove the cylinder head (para 3-19).

t o p of the cylinder block. The piston and rod

(3) Remove the carbon from the upper inner

cannot be removed from the bottom of the block.

surface of the cylinder liner.

(8) Reassemble the bearing cap and bearing

(4) If there is a ridge in the cylinder liner at the

shell.

top of the piston ring travel, remove the ridge with a

ridge cutter.

Figure 3-50. Piston and connecting rod assembly, removal and installation.

c. Disassembly.

and connecting

rod

assembly

numerical

(1) Refer to figure 3-51 and disassemble piston

sequence.

KEY to figure 3-51:

Oil control ring expander

1 Nut

Upper half oil control ring

2 Cap

Lower half oil control ring

3 Lower shell

Piston pin retainer

4 Upper shell

Piston pin

5 Bolt

Piston

6 Top compression ring

Piston pin bushing

7 Compression ring, grooves 2,

Connecting rod bushing

3 and 4

Connecting rod

8 Upper half oil control ring

Cylinder sleeve

9 Oil control ring expander

10 Lower half oil control ring

3-66