Yanmar 3TNV82A-B Service Manual page 224

ENGINE
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 6-136, (4)). Reinstall the oil ring
(Figure 6-136, (3)) with the end gap at 180°
from the expander end gap.
4. Reinstall the second compression ring
(Figure 6-136, (2)). This ring is identified by its
dark color and tapered face profile.
5. Reinstall the top compression ring
(Figure 6-136, (1)). This ring is identified by its
silver color and barrel-shaped face profile.
IMPORTANT
The oil ring expander (Figure 6-136, (4))
end gap must be located 180° from the oil
ring (Figure 6-136, (3)) end gap.
(4)
Figure 6-136
6. Stagger the piston ring end gaps at 120°
intervals (Figure 6-137, (1, 2, 3)). Do not
position the top piston ring end gap in line with
the wrist pin.
6-92
Crankshaft and Camshaft Components
1 – Top Compression Ring End Gap
2 – Second Compression Ring End Gap
3 – Oil Ring End Gap
Installation of Crankshaft
(1)
1. If removed, reinstall the keys and timing gear on
the crankshaft.
2. Reinstall new bearing inserts
(2)
(Figure 6-138, (1)) and thrust bearing
(Figure 6-138, (2)) in the cylinder block and
(3)
main bearing caps. Apply a liberal coat of clean
engine oil to the bearings and crankshaft
journals.
3. Place the crankshaft into the engine.
0001722B
The main bearing caps are numbered and
have arrows for proper positioning. The
No. 1 cap is at the flywheel end. The arrows
point toward the flywheel end of the engine.
4. Reinstall the main bearing caps
(Figure 6-138, (3)).
(1)
(2)
0001968
Figure 6-137
IMPORTANT
TNV DI Service Manual
(3)