1998-2001 Yamaha YFM600FHM Grizzly Factory Service Manual, Page 214Get this manual
MIDDLE GEAR
MIDDLE DRIVE SHAFT REMOVAL 1.Straighten: Punched portion of the nut (middle drive pinion gear) 2.Loosen: Nut (middle drive pinion gear) CD NOTE: Place copper plate between the teeth of the drive gear and the driven gear to lock them3.Remove: Nut (middle drive pinion gear) Middle drive pinion gear Shim(s)