2006-2009 Honda TRX680 (TRX 680 FA-FGA) Factory Service Manual, Page 450Get this manual
FRONT DRIVING MECHANISM
TROUBLESHOOTING
Consistent noise during cruising Oil level too [ow
Foreign matter contaminating gear oil
Worn or damaged bearing
Worn or damaged ring gear and pinion gear
Deformed ring gear or differential case
Improper tooth contact between ring gear and pinion gear
Gear noises while running Oil level too [ow
Foreign matter contaminating gear oil
Chipped or damaged gears
Improper tooth contact between ring gear and pinion gear Gear noise while coasting