2008 Arctic Cat 400/500/650/700 ATV Service Manual, Page 32Get this manual
2Select the 2WD position on the front drive selector switch; then turn the ignition switch to the ON position and select the LOCK position on the differential lock selectorThe front drive actuator should operate engaging four-wheel driveNOTE: It may be necessary to turn the handlebar or rock the ATV forward and backward to align the differential lock splines and allow engagement 3Return the differential lock selector to the UNLOCK position and listen for the front drive actuator to operateCD560A