2008 Arctic Cat ThunderCat ATV Service Manual, Page 73Get this manual
2Install flat washer, drive pin, and drive gear onto the oil pump shaft; then secure with snap ring (flat-side away from the gear)GZ312
6From the opposite end of the countershaft, install the highlow driven gear dog (A), thrust washer (B), bushing (C), bearing (D), highlow driven gear (E), and spacer washer (F)
3Install the water pump drive gear, driveshaft, and drive pin; then install the countershaft into the crankcase and secure with snap ring (flat-side away from the bearing)