Onan MJA Series Service Manual page 94

92 ENGINE DISASSEMBLY
2. Install the thrust washers and locking pins. Heavily oil thrust
washers to hold them in place.
:3 . Oil the bearing surfaces and install the crankshaft from the rear
of the crankcase, through the rear bearing plate hole.
4. Mount and secure the rear bearing plate. Use new gaskets.
5. Heat the timing gear on an electric burner or oven to about 350°F.
Install on the crankshaft and drive into place. Install the retaining
washer and lockring.
6. 4-CYLINDER ONLY. Set the upper half of the center main housing
on the crankshaft and rotate it into place. Be sure it is installed
with the side marked FRONT toward the crankshaft gear. Set the
2 positioning dowels on the upper bearing mount. Install the
center main bearing cap and torque the bolts to 97 - 102 lb. ft.,
Fig 3. 9.J.
7. Check the crankshaft end play. Use enough rear bearing plate gas ­
kets to provide .010" to .015" end play.
8. Install piston assemblies as per Sect 3.8.
:3.9.6 CRANKCASE
If, on the 4-cylinder models, the center main bearing support requires
replacement, the whole crankcase must be replaced or returned to the
factory
to
have a new housing fitted.
,
.
BOLT
CENTER MAIN~
IJ
lr-S'DE MARKED "FRONT"
BEARING C A P '
~'"
I
TOWARD CRANKSHAFT
- - - - - - I
j
GEAR
BEARING HALF
J::::::; =~-;.;-.
O:;:-J--.,
,/",--. i' : ..
,~
PLACE UPPER BEARING
/ / .
~-~.--'<\.
' HOUSING HALF IN POS­
CRANKSHAFT~
..
,>'\\lo!;
ITION INDICATED BY
;; "J
\,~
BROKEN LINE, ROTATE
DOWEL PIN
' I , ".-'"
~TO
POSITION.
z
1~
DOWEL PIN
BEARING
~
,., CENTER MAIN BEAR­
HALF INC HOUSING
(UPPER HALF)
BE SURE TO ALIGN OIL
HOLES IN BEARING
AND HOUSING
FIG 3. 9.J - CENTER MAIN BEARING (MJC ONLY)