JAC J2 - Page 81



Maintenance Manual for J2 Sedan
Mechanical Part of Engine
80
Standard value: 0.02 - 0.04mm + (0.01mm) expansion
Limit:0.1mm
⑬

Roundness
and
Cylindrica
lity
of Cra
nkshaft
Measure sizes of each main crankshaft journal and
main connecting rod journal at four different
positions as s
hown in the fig
ure.
■
The
difference
between
“X”
and
“Y”
of
“A”
and “B” represents the roundness.
■
The
difference
between
“A”
and
“B”
of
“X”
and “Y” represents the cylindricality.
Limits: For roundness: equal to or less than 0.05mm
For cylindricality: equal to or less than 0.05mm
Calibrate or replace the crankshaft if the measurements exceed the limits.
⑭

Clearance
of
Crankshaft
a.
Wipe
off oil
from the
crankshaft journal
and
the
inner surface
of bearing
shell.
b.
Mount
the
bearing
shell.
c.
Set the
plastic divicer
till
its width
equals to
the
width of
bearing shell. T
hen put
them
on the
journal alo
ng the axial line o
f journal.
d.
Lightl
y
mount
the
crankshaft bearing
shell
cover,
and
screw
the
bolt
till
to
specified torque.
e.
Dismount the
bolt
and
lightly take
off the crankshaft bearing shell cover.
f.
Measure
the
pressed
portion
of
plastic
divider
at
the widest point by the scale which is printed on
the plastic wire gauge bag.
Standard values: 0.02-0.04mm
Limit:0.1mm
Attention:
■
The
connecting
rod
journal
and
main
journal
of crankshaft should be rolled but
needn't to be machined to the reduced size.
Fi .1.1.067
Fig.1.1.068
Fig.1.1.069
Plastic Wire
Gauge

Round-angle Rolling Area
