Yanmar 4TNV98 Service Manual page 135

5. Apply a light coat of clean engine oil to the
bearing cap bolts and tighten the bolts to the
specified torque in two stages (1/2 then full
torque). See Special Torque Chart on page 6-25
for specifications.
Figure 6-135
6. Rotate the crankshaft to assure it turns freely.
7. Apply ThreeBond Liquid Gasket No. 1212 to the
mounting flange of the seal housing (Figure 6-136,
(2)).
8. Align the seal housing with the two dowel pins.
9. Reinstall seal housing and seal assembly.
10. Reinstall the flywheel (Figure 6-136, (1)) and
tighten the bolts to the specified torque. See
Special Torque Chart on page 73 for specifications.
Figure 6-136
4TNV98 & 4TNE98 Diesel Engine
Installation of Pistons
Do not allow the connecting rod to contact the
crankshaft journal during piston installation. Damage
to the crankshaft bearing journal may result.
4TNV98 Engine
1. Lubricate the piston, piston rings, and cylinder
with clean engine oil or assembly lubricant.
2. Rotate the crankshaft so the crankpin for the
piston being installed is near bottom dead center.
Ensure the piston ring gaps are located correctly
(Figure 6-137).
(1) Top Compression Ring End Gap.
(2) Second Compression Ring End Gap.
(3) Oil Ring End Gap.
3. Using a piston ring compressor, compress the
piston rings.
The piston and connecting rod must be installed in
the correct orientation. The orientation of the piston
to the cylinder is different depending on engine
model.
133
IMPORTANT
IMPORTANT
Figure 6-137
IMPORTANT
Section 3. Engine