1998-2001 Yamaha YFM600FHM Grizzly Factory Service Manual, Page 231Get this manual
TROUBLESHOOTING
DRIVE TRAIN
TROUBLESHOOTING
The following conditions may indicate damaged shaft drive components: Symptoms Possible Causes 1.A pronounced hesitation or "jerky" move- A.Bearing damagement during acceleration, deceleration, or B.lmproper gear lashsustained speed(This must not be confused with engine surging or transmission C.Gear tooth damagecharacteristics D.Broken drive shaft2.A "rolling rumble" noticeable at low speed; high-pitched whine; "clunk" EBroken gear teeth