2006 Honda TRX680 Rincon Factory Service Manual, Page 327Get this manual
DRIVETRAIN SYSTEM Shift the sub-transmission into neutralRemove the two bolts and the gear position switch from the crankcase coverGEAR POSITION SWITCH
Coat new O-ring with engine oil and install it onto new gear position switchAlign the long end of the switch pin with the" markInstall the gear position switch by aligning the switch pin with the slot in the crankcase cover being careful not to damage the switch pinInstall the bolts and tighten themRoute the gear position switch wire properly (page 1-20)
GEARSHIFT SWITCH
NOTE The AT can shift and the meter indicates the shift position (1 through 3) with the following conditions:Mode select switch at ESP (Electric Shift Program)Gearshift lever in rangeIgnition switch turned ON