TM 5-4320-302-14
6-16.
PISTON ASSEMBLY (CONT)
Location/Item
Action
Remarks
17. Piston ring
a.
Measure piston ring side
side clear-
clearance with new piston
ance
rings only. Measure side
clearance of each piston
ring with feeler gage in
its corresponding piston
ring groove in accordance
with the chart below.
NORMAL SIDE
SIDE CLEARANCE
CLEARANCE
WEAR LIMIT
inches
inches
PISTON RING
(millimeters)
(millimeters)
First or trapezoidal
0.0041 to 0.0057
0.0197
ring
(0.105 to 0.145)
(0.5)
Second or taper
0.0035 to 0.0048
0.0118
piston ring
(0.090 to 0.122)
(0.3)
Third or oil control
0.0016 to 0.0028
0.0059
ring
(0.040 to 0.072)
(0.15)
b.
If piston ring side clearance for any piston ring is
less than normal lower limit value given in chart,
replace piston ring and measure side clearance
again. If condition still exists, replace piston. If
side clearance for any piston ring exceeds wear
limit in chart, replace piston. Also replace
cylinder, if necessary.
18. Pistons,
If piston replacement is necessary, piston rings
cylinders,
must also be replaced. Normal sized pistons/
and piston
cylinders require normal sized piston rings.
rings
Oversized pistons/cylinders require oversized
piston rings.
6-117
