TM 9-2320-272-24-4
5-10. PISTON AND CONNECTING ROD MAINTENANCE (Contd)
c. Disassembly
1.
Remove four piston rings (1) from piston (6).
2.
Remove two snaprings (2) from piston pin bore (5).
WARNING
Pistons must be heated in hot water to remove piston pins. Do not
handle hot pistons with bare hands. Use protective gloves to avoid
burning hands.
NOTE
Mark piston and connecting rod so it can be reassembly in same
manner.
3.
Submerge pistons (6) and connecting rod (4) assemblies in container of hot water for fifteen minutes
to allow pistons to expand.
4.
Remove pistons (6) and connecting rod (4) assemblies from hot water with tongs or hook and place
in vise. Push piston pin (3) out of piston pin bore (5). Do not drive pins (3) out with hammer.
5.
Place pistons (6), piston pins (3), and connecting rods (4) on a numbered rack and hold for
inspection.
d. Cleaning and Inspection
NOTE
Ensure bearing caps remain assembled to mating connecting rods
at all times to avoid mixing.
1.
Clean connecting rod assemblies (7) (para. 2-14).
2.
Inspect connect rod assemblies (7) (para. 2-15).
3.
Visually check I-beam section (8) of connecting rod (4) for nicks, dents, and gouges. If nicks, dents,
or gouges are greater than 0.031 in. (0.787 mm), replace connecting rod (4).
4.
Inspect connecting rod assemblies (7) for cracks (para. 2-16).
NOTE
To accurately measure all connecting rod bearing cap bores, the screws
must be tightened to the operating torque specified in table 5-7.
5.
Install bearing caps (9) on connecting rod (4) with screws (10).
6.
Alternately tighten screws (10) with torque wrench in accordance with the sequence order in
Table 5-7. Connecting Rod Screw Tightening Sequence.
TORQUE VALUES
TIGHTEN SEQUENCE
NM
LB-FT
(95-102)
70-75
Step
l-Tighten to
(90-203)
140-150
Step
2-Tighten to
Step
3-Loosen to
(0)
(0)
(34-41)
25-30
Step
4-Tighten to
(95-102)
70-75
Step
5-Advance to
(190-203)
140-150
Step
C--Advance to
5-68
