Yanmar 4TNV98, Service Manual

Page: 123 / 246

4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 121
2. Apply a continuous bead of ThreeBond Liquid
Gasket No. 1212 to the outside diameter of a new
oil seal
(Figure 6-108, (2)) , and install in the gear
case cover. Apply lithium grease to the lip of the
seal.
Figure 6-108
3. Remove the rear oil seal (Figure 6-109, (3)) from
the seal housing (Figure 6-109, (2)) .
4. Apply a continuous bead of ThreeBond Liquid
Gasket No. 1212 to the outside diameter of a new
oil seal
(Figure 6-109, (2)) , and install in the
housing. Apply lithium grease to the lip of the seal.
Figure 6-109
Measure Crankshaft Bearing Oil Clearance
Oil clearance should be checked during disassembly
to determine the extent of wear, and during
assembly to ensure long engine life. The same
procedure is done for both connecting rods and
main bearings.
Inspection of Cylinder Block
1. Ensure that oil passages are clear and
unobstructed.
2. Check for discoloration or evidence of cracks. If a
fracture is suspected, use the color check method
or the Magnaflux method to determine if the
cylinder block is fractured.
3. Inspect cylinders for roundness, taper, or
evidence of scoring. Collect and record the
measurements. Consider honing, reboring or
replacing the cylinder block if the measurements
are not within specification.
• Take measurements at three places
(Figure 6-110) (a, b, c), and in two directions (d
and e) in each cylinder.
Figure 6-110