CYLINDER
BLOCK
SERVICE
Connecting
Rod
1. Using a connecting rod aligner, check each connecting
rod for bending and distortion. If necessary, correct or
replace the rod.
2. Measure the connecting rod thrust clearance with a rod
assembled on the crankshaft. If the clearance is exces-
sive, replace the rod assembly.
!
CONNECTING
ROD
THRUST
CWRANCE
Crankshaft
1. Measure the crankshaft bend, If excessive, repair or
replace the crankshaft.
CRANKSHAFT
0.0.
2. Check the crankshaft journals and pins for damage,
seizure and other faults.
If
excessively worn or damaged,
machine to the undersize diameter. At the same time,
replace the corresponding main bearing or connecting rod
bearing with the same undersize bearing. When machin-
ing a crankshaft journal
or
pin to the undersize one, be
sure to finish its fillets to R2.S mm. Check that all oil
passages in the crankshaft are clean and open.
(JOURNAL)
R2.5~
(PIN)
R
2.5
3. Check the crankshaft end play. If the specified limit
is
exceeded, replace the flanged No
..
3 main bearing.
To
check the end play, install the
ma~n
bearings, crankshaft
and main bearing caps, then tighten the cap bolts to the
specified torque. Measure the end play with a dial gauge
held against the front end
of
the crankshaft.
Main
Bearings
and
Connecting
R"d
Bearings
Check the surface
of
each bearing for flaking, melting, seiz-
ing and poor contact. If any
of
these conditions exist, replace
the bearing.
Fit the main bearings to the cylinder block and the connect-
ing rod bearings to the connecting rods. Tighten the bolts to
specification. Measure the
J.D.
of
eac~
bearing. Then mea-
sure the
0.0.
of
the crankshaft journals and pins
to
calculate
the oil clearance (a plastigauge may be used). If any oil clear-
ance is excessive, replace the corresponding bearing.
If
an
excessive clearance still remains even after replacement
of
the bearing, grind the crankshaft to
th!f!
undersize
0.0.
and
install the same undersize bearing.
MEASURING
CONNECTIN~
ROD
BEARING
1.0.
Engines & Generators
25
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