Valmet 309 - Connecting Rods and Pistons; A. REMOVING THE CONNECTING ROD AND PISTON; B. CHECKING AND REPLACING THE CONNECTING ROD BEARINGS; OVERSIZE PISTON PIN BEARING BUSH

2.
@NiECTI
NG ROOS AND PISTONS
REIII)VI
l{G Ir€
@Nt€CTt
t{G R00 AID P|STo|I
Rqpve
+ho ol I sumo
and
ihe oll lnlet and
pressure p
lpes.
Renpve +he
cyllndor
heöd
(
s€€
Instrugtloos,
polnt
5 | A).
Scrape off the
posslble
soo+ ln
ihe
cyllnder
llner
top edge.
lf nec€ssory, uso a
reamer 10
remove
+he
sharp rear edg€ ln the
plsion .lng
+op
dead
cenir€.
Remove
+he connecilng
rod
bearlng caps
and
b€arln9
shells. lf
you
lntend
fo fl+ +he
same
shells
back, nole +helr
correc+
order.
Press
the
connecilng
rod
and
pls'ton off
+he
cyllnder by uslng
a ,ooden haftEr
handlo
or
equ I
va
len+.
RqrDve
ihe
plsion
pln
clrcllps.
Heai-
ihe
plston
evenly to
a ienperoture
of t 00oc
and
push
out
th6
pls+on pln
monually uslng
a
suliable
drllt.
Noiel Due
to
I luc+uat Ing
to lerances
the
plston pln
cön be removed
manually
even rhen
cold. tf
ihe
pln
does not com€
off
rhen
pressed
by
hand,
do no+ +ry lo
iap
l+ off
b€for€
heaflng, becouse
+h6
pln
ls fltied
too flghtly
and
the plsfon may be dömaged.
CIICKI
NG AIO REPLACING
THE
CONI€CTI
NG
ROD
EEAR
Il|GS
Clean
the connectlng
rod 6nd
the b€arlng
shells
carefully.
Place
tho bearlng
shells
ln
thelr
flghten the
bearing caP
(9O
lfi JO9, 5ll,
4ll
of the 612 enoln6
flrst
€nd ihon oach :crer
9Oo.
connectlng
rod scrsrs
lo
the +orque
ol l0
Nm
Pr€ss
+he ner
bush
In lts
place.
Ensurg
ihai
the ol I hole In
ihe bush colncldes
rlth
'the
respectlve
hole
in the
connocilng
rod. Al+er
flttlno
ream ihe bush to aitaln
lts corrasl
dlametår
(s6
techntccl
datc
iconnesil
ng
rodr ),
OVERSI4
PI STOII
PI}I BEAR ING
BUSH
It
requlred,
you
can flx In
ihe connsc+lng
rod
snall
end a bush
wlih an overslze oufslde
dla-
nEfor. Machlne
+he connectlng
rod small
end
bearlng houslng
accoidlng io
the fables
bololr:
Order
oe
Enoine
Bearing housing
oroer
number
for bearinq
bu
309 40,500
.
40,525
8360 38605
3r1
411
6r1
44.500 44.525
83s3
28326
612 48,500...48,525
8363 38606
B.
t.
corresl
posltlons
önd
io +he corr€ci
torque
lnd 6ll).
Tlghten
ihs
Alier flt+lng
ream
+he
bush +o
(s€
tschnlcal data
'conncsil
n9
INSPECT It{G T}€ @NTCCTI
iG ROD
lls correct
slz6
rodt
).
414
2. Measure the bsorlng cleorances
rl-th a dlal
Indlcafor zor€d
to ihe crankshaft
b6örlng
journal.
Max
permlsslblg
b€arlng clearance
In
+he
connectlng
rod
blg end bearlngs
ls
0rt4
mm. I f necessory,
gr
I
nd
-the
crankshaft
bearlng
journöls
6nd Install the underslzed
bearlngs
dellvgred
as sparg
parts.
J.
It
ihe plston pln
bush ls too rorn,
remova
ihg
bush
by
presslng
rlth
a sullable drlff.
4-12
4 16
dl fferenl
etglne iypes
31'1,411,611
The
connecilng
rods
of