2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 250Get this manual
REAR AXLEFINAL DRIVE GEAR AND DRIVE SHAFT REAR AXLE REMOVAL 1.Remove: Rear axle (with dust seal) O-ring
CAUTION:
Never directly tap the axle end with hammer, since this will result in damage to the axle thread and splineAttach suitable socket on the axle end and tap it with soft hammerPull out the rear axle to the right
FINAL DRIVE GEAR DISASSEMBLY 1.Remove: Bearing retainer (final drive pinion gear) NOTE: Use bearing retainer wrench 1Bearing retainer wrench: PNYM-04050, 90890-04050