Shibaura CM284 - Page 27

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9) Crankshaft
Inspection
(1) To measure run-out of the crankshaft, support the
crankshaft using a V block as shown in the right
figure, apply a dial gauge to the crankshaft center
journal, read the indication on the dial gauge rotating
the shaft one turn gently. If the service value is
exceeded, correct or replace.
(2) Check the crankshaft oil seal for damage or wear on
the contact surface and oil hole clogging.
(3) Check the crankshaft journal and pin for damage,
irregular wear (ellipticity, conicalness) and shaft
diameter. If the service limit is exceeded, replace the
bearing (bush) and/or crankshaft. Measure the
dimensions of the journal and pin in the AA and BB
directions at the position 1 and 2 avoiding the oil
holes.
Irregular wear limit of crankshaft journal and pin
0.05 mm
Crankshaft run-out (mm)
Standard assembling value Service limit
L
ess t
h
an
0
.
03
0
.
06
039X
040X
Model J843
Journal and pin size
Shaft dia. at crankshaft journal (φ) Shaft dia. at crankshaft pin (φ)
S.T.D.
Outside dia.
finishing
dimension
Repair value
Outside dia. finishing
dimension Repair value
57.957 – 67.970 Less than 57.90 43.964 – 43.975 43.90
Model N843L
Journal and pin size
Shaft dia. at crankshaft journal (φ) Shaft dia. at crankshaft pin (φ)
S.T.D.
Outside dia.
finishing
dimension
Repair value Outside dia. finishing
dimension Repair value
67.957 – 67.970 Less than 67.90 51.964 – 51.975 Less than 51.90
* Replace the crankshaft if diameter is below the repair value.