Yamaha GRIZZLY 660 YFM66FAV Owner's Manual page 326

5. Fill the final gear case with the specified
amount of the recommended oil.
Recommended oil:
SAE 80 API GL-4 Hypoid gear oil
Oil quantity:
0.25 L
CAUTION:
_
Be sure no foreign material enters the final
gear case.
_
6. Install the filler bolt and tighten it to the speci-
fied torque.
Tightening torque:
Final gear oil filler bolt:
23 Nm (2.3 m·kgf)
7. Check for oil leakage. If oil leakage is found,
check for the cause.
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