2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 76Get this manual
ENGINE (300) 789If drum bearing was replaced in the starting clutch housing, press the drumshaft into the housing until fully seatedClean the inside of the starting clutch drum and lubricate the drum and one-way clutch with engine oilInstall one-way clutch in starting clutch drum with the flanged side toward the hub, using rotating motion
Flange side toward hub