Yamaha GRIZZLY 660 YFM660FAT Owner's Manual page 332

5. Fill the differential gear case with the recom-
mended oil.
Recommended oil:
SAE 80 API GL-4 Hypoid gear oil
Oil quantity:
0.28 L
CAUTION:
_
Be sure no foreign material enters the differen-
tial gear case.
_
6. Install the differential gear oil filler bolt, and
then tighten it to the specified torque.
Tightening torque:
Differential 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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