Weifang 495 Operation And Maintenance Manual page 69

the per -nlissible limit, it should be renewed.
. On tile joint face
~Jf
each bearing half, there is sheared locating
lug which is just to be set into the locating slot on the bearing
housing to prevent the shell from axial nlovement.
The main bearings can be
classifie~·
il1tO
two groups i1,::cording'
to tlleir
width. The
first
and the fifth
:tIiain bearing-are
wider while
the second, the third and th'e fourth main bearirlgs·are narrower.
The main bearing upper halv'es are also different from the lower
halves.
The
one provided
with
an
oil hole'
is
the upper
half.
All the connecting rod bearing halves are the same in struc-
ture and size .
.In order
to
let
the crankshaft taking
axial load.
the thrust
riIlgs are fitted 011 both sides of the fifth main bearing housing.
'There are two oil
grOO\TeS
on the side' of
alloy
layer
of~ach
thrust
ring,
wh";ich
shc)uld face to the
cra~kshaft
slloulder arid never put
the inside surface
out~t'vard.
.
The main bearing caps and conne.cting rod caps are fastened
by
11igh strength
bolts
.tig11tened with specified torque and locked'
by
lock .tab find lock \vires respectively.
Both the front and rear ends of the crankshaft are sealed
by
means of two rubber seals. In order to make the sealing more reli-
able ,an oil slinger is mOllnted
ill
the
~ront
of the rubber seal.
The flywheel is tightened onto the
flang~
at
the crankshaft
rea-r end
b~f
six
high strength
b~lts
and located angularly
by
a dow-
el pin.
There are graduation lines of
2°
crank angle each r;narked on
the outer rim of the
flywheel,
presenting the top dead centre and
the advance angles from 10° to' 30° for the pistons of the first and
fourth cylinders.
34