Checking The Crankshaft - SHERCO 250 SEF-R Workshop Manual

Checking the crankshaft

Radial play of the big end bearing :
 Place the crankshaft in a set of V blocks and
install a dial indicator as shown [A].
 Push the rod [B] in the direction of the
indicator and then push it in the opposite
direction. The difference between these two
readings is the radial play.
Radial play of the big end bearing:
Standard: 0.015 mm – 0.020 mm
Tolerance limit: 0.06 mm
If the radial play exceeds the tolerance limit
the crankshaft must be replaced.
Lateral movement of the big end :
 Measure the lateral movement of the big end
[A].
Lateral movement of the big end:
Standard: 0.2 mm - 0.3mm
Tolerance limit: 0.55 mm
If the lateral movement of the big end
exceeds the tolerance the crankshaft must
be replaced
Checking the run out :
 Place the crankshaft in a lathe or suitable
support, place dial indicators as shown.
 Turn the crankshaft and record the readings.
The maximum
readings is the crankshaft run out.
Run out:
Standard: 0.02 mm maximum
Tolerance limit: 0.08 mm
If the run out exceeds the tolerance, replace
the crankshaft or straighten it so that it
meets the tolerance.
difference between the
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