1998-2001 Yamaha YFM600FHM Grizzly Factory Service Manual, Page 124Get this manual
DIFFERENTIAL GEAR OIL REPLACEMENT STEERING SYSTEM INSPECTION 4.Drain: Differential gear oil 5.1nstall: IXl19 Nm (1.9 kg, 13 ft Ib) Drain plug
Check the gasket (drain plug)If it is damaged, replace it with new one6.Fill: Differential gear case
Periodic oil change: 0.7 (0.62 Imp qt, 0.74 US qt) Total amount: 0.67 (0.59 Imp qt, 0.71 US qt) Recommended oil: SAE 80 API "GL-4" Hypoid gear oil
Take care not to allow foreign material to enter the differential gear case