6-27.1. PISTON - MAINTENANCE INSTRUCTIONS (Continued).
When installing the top compression (fire) ring, be sure tapered face marked "T"
or "top" is toward the top of the piston.
g. Stagger compression rings (4 and
Rotate rings on
5) gaps around the piston.
h. Install ring expander (7) in oil
control ring groove. Install
with the legs of the free ends
toward the top of the piston. With
the free ends pointing up, a
noticeable resistance will be
encountered during installation
of the piston if the ends of the
expander are overlapped and
corrective action can be taken
before ring breakage occurs.
When installing the oil control rings, use care to prevent overlapping the ends of
the ring expanders. An overlapped expander will cause the oil ring to protrude
beyond allowable limits and will result in breakage when the piston is inserted in
the ring compressor during installation in the cylinder liner. Do not cut or grind the
ends of the expanders to prevent overlapping. Cutting or grinding the ends will
decrease the expanding force on the oil control rings and result in high lubricating
Install the upper and lower halves
of the oil control rings (8).
Install by hand. Do not use tool.
Install the upper half with the gap
180from the gap in the expander.
Then install the lower half with
the gap 45from the gap in the
upper half of the ring. Make sure
the scraper edges are facing down
(toward the bottom of the piston).