to avoid distorting them, and tapping the cap
lightly on one side and then the other.
CRANKSHAFT REMOVAL
Once the bearing caps have been removed, lift
the crankshaft out of the engine block. Usually
one or two people do this seemingly simple
operation by hand. With larger crankshafts, use
a hoist (fig. 3-25), lifting above the center with
a rope sling around two of the throws.
CAUTION
Do not bang the crankshaft around
causing damage that will have to be
repaired before the crankshaft may be put
back in service.
CRANKSHAFT JOURNAL CHECK
The preferred method of measuring crank-
shaft journals is as follows. Remove the
crankshaft from the engine block and clean the
surfaces to be measured. Using the appropriate
outside micrometer, measure the journals at
several points around and across the bearing
surface (fig. 3-26). Measurements around the
journal will show if the journal is out of round.
Those measurements across the surface show if
the journal is tapered. Journals that are
Figure 3-25.Crankshaft removal using hoist.
Figure 3-26.Measuring the journals at different points
around the diameter and along the length of the
bearing surface.
tapered or out of round more than .003 must be
reground. BE SURE THAT YOU ALWAYS
REFER TO MANUFACTURERS SPECIFICA-
TIONS WHEN PERFORMING ANY CRANK-
SHAFT WORK.
CHECKING OF BEARING FIT
You should always check bearing fit or oil
clearance when installing new bearings. When the
bearing caps are off, you should measure the
journals so that you can detect wear, out of
roundness, or taper.
You can check bearing clearance with either
feeler stock or Plastigage. Plastigage is a plastic
material that is flattened by pressure. The amount
it flattens indicates the amount of clearance.
Before checking bearing clearance with Plasti-
gage, wipe the journal and the bearing clean of
oil. Then place a strip of the Plastigage lengthwise
in the center of the bearing cap (fig. 3-26). Install
the cap next and tighten it into place. When the
cap is removed, you can measure the amount of
flattening of the strip with a special scale (fig.
3-26). Do NOT remove the flattened strip from
the cap or the journal to measure the width, but
3-23
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