Yanmar 4TNE98, Service Manual, Page: 132 / 246

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 130
IMPORTANT
Always use a piston ring installation tool (expander)
when installing piston rings. Never attempt to install
piston rings by hand.
3. Reinstall the oil ring expander (Figure 6-133, (4)) .
Reinstall the oil ring (Figure 6-133, (3)) with the
end gap at 180° from the expander end gap.
4. Reinstall the second compression ring (Figure 6-
133, (2)) . This ring is identified by its dark color
and tapered face profile.
5. Reinstall the top compression ring (Figure 6-133,
(1)). This ring is identified by its silver color and
barrel-shaped face profile.
IMPORTANT
The oil ring expander
(Figure 6-133, (4)) end gap
must be located 180° from the oil ring (Figure 6-133,
(3)) end gap.
Figure 6-133
6. Stagger the piston ring end gaps at 120° intervals
(Figure 6-134, (1, 2, 3)) . Do not position the top
piston ring end gap in line with the wrist pin.
Figure 6-134
(1) Top Compression Ring End Gap.
(2) Second Compression Ring End Gap.
(3) Oil Ring End Gap.
4TNE98 Engine
1. Select the parts needed to assemble the piston
and connecting rod for the No.1 cylinder.
2. Lubricate and insert the wrist pin bushing (Figure
6-70, (1)) into the small end of the piston rod.