1998-2001 Yamaha YFM600FHM Grizzly Factory Service Manual, Page 344Get this manual
FAULTY DRIVE TRAIN FAULTV DRIVE TRAIN
The following conditions may indicate damaged shaft drive components: Symptoms 1.A pronounced hesitation or "jerky" movement during acceleration, deceleration, or sustained speed(This must not be confused with engine surging or transmission characteristics 2.A "rolling rumble" noticeable at low speed; high-pitched whine; "clunk" from shaft drive component or area3.A locked-up condition of the shaft drive mechanism, no power transmitted from the engine to the front andor rear wheelsPossible Causes A.Bearing damageB.lmproper gear lashC.Gear tooth damageD.Broken drive shaftE.Broken gear teethF.Seizure due to lack of lubrication?