Onan MJA Series Service Manual page 63

61
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.,:,
OIL SYSTEM
3.5.1 MAINTENANCE
Periodic oil system maintenance should include changing crankcase oil,
cleaning the crankcase breather (Sect 3. 5. 7), cleaning rocker box oil
. lines (Sect 3.5.4), and replacing the oil filter (Sect 3.5.6). Consult
the periodic service chart for service periods.
Always use a heavy duty detergent
oil classified by A.
P.
1.
for service
Above 30
0
F SAE 30
"DG" or "MS/DG". Use the proper
Below 30 0 F SAE 5W-20
SAE number for the expected ambient
temperatures. Do not use service "OS" oil.
3.5.. 2 OIL PUMP
The oil pump is mounted on the crankcase behind the gear cover and is
driven by the crankshaft gear.
3.5.2.1 Removal
1.
Remove the gear cover (Sect 3.10.2) and oil base.
2 . Unscrew the intake cup from the pump.
3. Remove the crankshaft lock ring and gear retaining washer.
4.
Loosen the two capscrews holding the pump and remove the pump.
. 3. 5.2.2 Repair. - Except for the gaskets, component parts of the pump
are not individuallyavailable.
If
the pump is defective or excessively
worn, replace it. Disassemble the pump by. removing the two capscrews
holding the pump cover to the body. .
Inspect for excessive wear in gears
REAR BEARING
and shafts. To improve pump per-
PLATE­
formance, adjust the gear end clear­
ance by changing the gasket thickness
between the pump body and cover.
Use the thinnest gasket that permits
free movement of the pump shaft.
OilJ?-.ll parts when reassembling the
pu'
~
3.5.2.3 Installation. - Before instal­
ling, fill the pump intake and outlet
withQil for priming. Mount the pump
on the engine. and adjust for. 005"
lash between the pump gear and
FIG 3.5. B - BY-PASS