2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 236Get this manual
TROUBLESHOOTING Troubleshooting Chart When basic condition "a" and "b" exist, check the following points: Elevate and spin both wheelsFeel for wheel bearing damageNO YES
Replace the wheel bearing(Refer to "STEERING SYSTEM" and "REAR SHOCK ABSORBER AND SWINGARM" in CHAPTER 8
Check the wheel nuts and hub nuts for tightnessYES
Torque to specification(Refer to "FRONT AND REAR WHEELS" in CHAPTER 8
Check the constant velocity jointFeel for bearing damageYES
Constant velocity joint bearings and differential gear bearings are probably not damagedRepeat the test or remove the individual components