2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 244Get this manual
CONSTANT VELOCITY JOINTS AND DIFFERENTIAL GEAR
3.Check: Free play (thrust movement) Excessive play Replace the joint assembly
DIFFERENTIAL GEAR ASSEMBLY 1.Measure: Gear lash Refer to "DIFFERENTIAL GEAR LASH MEASUREMENT AND ADJUSTMENT"2.Install: Gear motor Refer to "FEATURES" in CHAPTER 1