2008 Arctic Cat 400/500/650/700 ATV Service Manual, Page 262Get this manual
3Install the 3rd driven lock washer (left side)Lock it into the groove closest to the 5th driven gear (as noted in disassembling) by rotating it when it is in the groove
! CAUTION
It is very important to assure the oil feed hole in the bushing and oil supply hole in the driveshaft alignIf not aligned, engine damage will result
6In order, install the 3rd driven gear, lock washer (right side), and snap ring onto the driveshaft