NEXON BS VI - SERVICE MANUAL

274 / 1003

1.5L REVOTORQ BS VI ENGINE
70
M. CRANK SHAFT
Clean and carry out visual inspection of crank shaft
for the following:
1. Overheating of journals, this is indicated by
bluish brown color.
2. Scoring marks on journals
3. Cracks, which should be checked on magnetic
crack detector
4. Check crank shaft run out by supporting it on V-
block at 1st and 5th main bearing journals.
5. If run out exceeds permissible limits, straighten
crank shaft in cold condition on press carefully.
6. Similarly check lateral and radial run outs of
flywheel mounting flange.
7. Check crank shaft main bearing and crank pin
journal dimension.
8. Record the readings in the format given at the
end of this group.
9. If necessary, grind crank shaft main bearing and
crank pin journals to next under-size.
10.Maintain correct fillet radius for journals
11.Care must be taken during grinding to ensure
that width of journals is not increased.
12.Should it be necessary to grind sides of 4th
main bearing journal, grind it to next undersize.
-chamfer oil holes on journals to avoid
scoring of new bearing shells.
14.Finish journals by lapping them with 320 grit
lapping cloth of suitable width.
15.After grinding recheck main bearing and crank
pin journal dimensions.
16.Also recheck run out of crank shaft.
17.Thoroughly clean crank shaft with standard
cleaning solution. Use wire brush for cleaning
oil holes.
NOTE
It is essential to recheck crankshaft for cracks and
balance after grinding.
18.Apply grease to all machined surfaces, if crank
shaft is to be stored. Crank shaft must always
be stored in vertical position.
19.Thoroughly clean main bearing caps and
corresponding machined surfaces of
crankcase.
20.Install main bearing caps without bearing shells
in their respective positions on crankcase.
NOTE
Ensure that the serial numbers on crank case and
main bearing caps are matching. Also caps are in
order and notches forbearing shells are on same
side.