Figure 3-63. Piston and connecting rod (for engine model 687C-18-ES), exploded view.
(2) Inspect rings for cracks, breaks, or excessive
CAUTION
wear. Axial clearance of compression rings must not
exceed 0.002 inch, and oil rings 0.006 inch. Insert rings
Lubricate piston, rod, and rings
in cylinder liner and check gap. Compression ring gap is
before installing in cylinder liner.
between 0.023 and 0.028 inch. Oil ring gap is between
0.016 and 0.028 inch.
(1) Reassemble piston and connecting rod by
(3) Inspect upper and lower bearing halves for
reversing procedures in steps (3) through (6) of a above.
pitting, burned, or worn condition. Replace defective
bearing halves. Oil clearance should be between 0.002
(2) Install by reversing the procedures in steps (1)
and 0.004 inch. It must not exceed 0.006 inch.
and (2) of a above.
(4) Measure diameter of piston. Bottom should not
measure less than 4.494 inch. Top must measure not
3-58. Piston and Connecting Rod (Engine Model
less than 4.473 inches. Replace pistons that do not
D333TA)
conform to the above measurement t.
(5) Check rod bearing-to-pin clearance. Clearance
a. Removal and Disassembly.
should be between 0.0015 and 0.003 inch. It must not
exceed 0.008 inch.
(1) Remove engine (para 2-9).
(6) Inspect rods for twist and misalignment. Replace
(2) Remove cylinder head (para 3-55b).
defective rods.
(3) Remove oil pan (para 3-44).
(4) Rotate crankshaft until piston is at top dead
Reassembly and Installation
c.
center, then remove two cotterpins (1, fig. 3-64), nut (2),
and connecting rod cap.
NOTE
NOTE
When installing rings on piston, be
sure gaps are staggered. Every other
When bearing halves are not to be
ring gap must be on opposite side of
replaced, keep them together with
piston.
rod for reassembly in same position.
3-74
