Onan MJA Series Service Manual page 93

.I1;NtilNE IHSASSE MBLY
91
REAR
BEARING PLATE "",,:""!it
' " "' LOCK PIN .1
1.. THRUST WASHER ­
ALIGN OIL t::!OLES
lli,-I-+ ­
~--MAIN BEARING
:i!
~~~a-_~M~UST BE FLUSH WITH
r-,
NStDE SURFACE---I,
i " ' - - - -
LOCK PIN ..
~
FRONT
ILSEAL~
INSTALL FLUS
WITH OUTSIDE
SURFACE
P FACING
OUT
FIG 3. 9. I - MAIN BEARING INSTALLATION
Undersize bearings and connecting rods are available to rework the shaft
to .010", . 020", and. 030" undersize.
3.9.5.4 Bearings, Main. -
If
the main bearings' clearances are great ­
er than the limits, Sect 9, the bearings are worn, grooved or broken,
replace them. Precision replacement iYea:ring inserts and thrust wash ­
ers are available for all main bearings. Don't attempt to ream the
bearings.
Align the oil holes and press the new bearings into the front and rear
housings. Insert the center bearing on the
MJe
when the crankshaft
is
reinstalled.
3.9.5.5 Oil Seal, Rear. - The rear oil seal is in the rear bearing plate.
If damaged, drive it out from the inside of the plate. Apply fibrous or
stiff cup grease to the inner surface of new seal. This provides a better
seal and protects the seal during. installation. Using the oil seal install ­
ing tool, install the new seal with the, rubber lip facing outward (open
side facing in), Fig 3.9. J. Drive the new seal flush with the rear sur­
face of the bearing plate. Leave the seal installer on during. bearing
plate installation to protect the oil seal.
3 ..9.5.6 Installation. - After each installation step, check the crank ­
shaft to
be
sure it is not frozen into place.
1.
Press the front and rear main bearings into place, aligning the
bearing and bearing housing oil. holes. Don't attempt to drive a
bearing into a cold block or rear bearing plate.