Yamaha ULTRAMATIC KODIAK 400 YFM400FAR Owner's Manual page 304

5. Fill the differential gear case with the speci-
fied amount of the recommended oil.
NOTE:
_
G
Do not exceed the specified differential gear
oil quantity when filling. Overfilling will cause
the oil to seep out of the breather hose during
and after riding.
G
The differential gear oil level cannot be
checked. The differential gear case capacity
is greater than the recommended oil quantity,
therefore the oil level cannot be accurately
checked from the oil filler cap hole.
_
Recommended oil:
SAE 80 API "GL-4" Hypoid gear oil
Oil quantity:
0.4 L
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