Onan MJA Series Service Manual page 91

0::1
ENGINE
JJISASSlt; MJ::)L Y
3 . 9. 4. 4 Camshaft Bearings. -
Th~
cam shaft bearings sbould be re ­
placed if the clearance to the camshaft is greater than specified; or if
. tbe bearingssbow cracks, breaks, burrs, excessive wear, or other
defects·> .
The camshaft to bearing clearance sbould be .0012" to .0037". To
check the rear bearing, remove the expansion plug at tbe rear of the
crankcase.
Press new bearings into place, Fig 3.9. E. Press the rear bearing
flush with the bottom of the expansion plug recess. Press the front
t;
bearing in flush with the crankcase front surface so the crankcase and
bearing oil passages are aligned. Don't attempt to ream the bearings,
they are a precision type. After the rear bearing is installed, insert a
new expansion plug in the recess, using sealing compound, and expand
it into place with sharp blows at its center.
3.9.4.5 Installation, Camshaft Assembly. ­
1. Install the key and press the camshaIt g~ar On its shaft.
2. Install the governor components, Sect 3.9.3 onihe camshaft.
3. Slide the thrust wasber onto the shaft.
4.
Lay the engine on side or end and insert the pushrod tappets.
5. Install the camshaft assembly in the engine. Align the timing
marks on the camshaftg:E1aJ'.and crankshaft gear, Fig 3. 9.G.
\~
'"
THE:SE MARKS
MUST COINCIDE
WHEN lNSTALL ­
INGTIMING
GEARS
.s.2',1fH
-;.-::.. 'i'.
~
'FIG 3,is":F-MEASURING CAM ­
FIG 3.9. G - ALIGN1NG
SHAFT ENDPLAY TIMING GEARS