Yamaha YFM660FS Grizzly 4x4 Supplementary Service Manual page 92

GEN
FEATURES
INFO
2WD
Power is transmitted as follows: middle gear → front drive shaft → drive pinion gear 7 → ring gear
5 → differential pinion gear 4. In the 2WD mode, the left differential side gear 3 and the drive
clutch 2 are not engaged, therefore, the left side gear runs idle and does not transmit power to the
left front constant velocity joint.
1 - 3