TM 55-1930-209-14&P-21
(5)
Install oil control rings by hand with the scraping edge of each ring down.
(6)
Install expander in upper oil ring groove being careful not to overlap ends.
CAUTION
Oil ring expander must be completely seated in oil ring groove. If ends of expander
should overlap, oil ring will protrude slightly and be broken when piston ring compressor
is installed over piston, or when piston and rod assembly is installed in cylinder liner.
(7)
Install top oil ring, with gap 180° from ends of expander. Install bottom oil ring with gap 45° from top oil
ring gap. Recheck to make sure ends of expanders are not overlapped.
CAUTION
Do not at any time, cut off or grind ends of oil ring expander to prevent ends from
overlapping. This will decrease the tension on oil control rings and result in high oil
consumption.
(8)
Install second set of oil rings in a similar manner.
(9)
Install four compression rings on piston using a ring expander. Stagger ring gaps around piston with gap of
each succeeding ring at least 45° and not more than 90° from preceding ring gap. Proceed either clockwise or
counterclockwise with ring gaps.
NOTE
When installing top compression (fire) ring with tapered face, be sure and install ring with
oxide (rust) colored side facing toward top of piston.
b.
Installation
(1)
Rotate crankshaft until connecting rod journal is at bottom of its travel. Wipe journal clean and lubricate it
with clean engine oil.
(2)
Install two connecting rod bolts and upper bearing half in assembled connecting rod.
(3)
Use a suitable ring compressor and apply clean engine oil to piston rings and inside of ring compressor.
(4)
Position piston and connecting rod assembly so that identification number on rod is facing serial number
side of engine block.
(5)
Start skirt of piston into cylinder block and lightly tap top of piston into block with wooden handle of a
hammer until it clears ring compressor. Pull piston and rod assembly down until upper bearing half seats firmly on
crankshaft journal.
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