Yanmar 4TNV98 Service Manual page 127

4. Use the color check method or Magnaflux® to
inspect the crankshaft for cracks. Replace the
crankshaft if evidence of fractures are found.
5. Measure the outside diameter of each crankpin
(Figure 6-120, (2)) and main bearing journal
(Figure 6-120, (1)). See Crankshaft on page 70
for specifications. Take measurements at several
places around each bearing surface. If not within
specification, grind the journals and install
undersize bearings, or replace the crankshaft.
Figure 6-120
4TNV98 & 4TNE98 Diesel Engine
Inspection of Camshaft
1. Use V-blocks and a dial indicator to check
camshaft bend (Figure 6-121). Place the indicator
on the center bearing journal.
2. Rotate the camshaft and observe the runout. See
Camshaft on page 68 for specifications.
3. Measure the height of each lobe
(Figure 6-122, (1)). See Camshaft on page 68 for
specifications.
4. Measure the diameter of the gear end (Figure 6-
123, (1)), intermediate (Figure 6-123, (2)), and
flywheel end (Figure 6-123, (3)) bearing journals.
See Camshaft on page 68 for specifications.
125
Figure 6-121
Figure 6-122
Section 3. Engine