TM 5-4310-379-14
5-20.
Pistons and Connecting Rods (Cont).
(10)
Hold piston upside down in the cylinder liner and check the piston-to-liner clearance. Check the clearance in four
places, 900 apart using feeler-gage set as follows:
NOTE
The spring scale, attached to the appropriate feeler gage, is used to measure the amount force in pounds
required to with draw the feeler gage from between piston and liner. The piston-to-liner clearance will be
.001 in. (.002 cm) greater than thickness of feeler gage used.
(a)
Select a feeler gage with a thickness that will require a pull of six pounds to remove. Feeler gage must be
perfectly flat and free of nicks and bends.
(11)
Insert one ring at a time inside cylinder liner and far enough down in the bore to be within normal area of ring
travel.
(12)
Use piston to push ring down to be sure it is parallel with top of liner, then measure ring gap with feeler gage.
Refer to table 1 for specified ring gaps.
Table 5-2.
(13)
Check piston ring clearance in the piston ring grooves as shown in Table 5-2.
(14)
Inspect connecting rod for cracks by using the magnetic particle method.
(15)
Inspect spray nozzle at upper end of connecting rod to make sure holes are open and replace if damaged.
(16)
Using connecting rod nozzle remover and press, press nozzle out of connecting rod.
(17)
Inspect connecting rod bushings for indications of scoring, overheating or other damage.
NOTE
Diameter of new piston pin is 1.4996-1.500 in. (3.8089-3.8100 cm). Worn piston pin clearances up to
.010 in. (.002 cm) are satisfactory.
5-76
