2010 Polaris Sportsman 850 Service Manual, Page 168Get this manual

TRANSMISSION Transmission Assembly Thoroughly clean the transmission case halves and shaftsInspect all seals and O-rings
shift shaft was disassembled, install the detent gear with the step facing the O-ringStep If the bellcrank shift shaft was
disassembled, install the gear sector with the step facing the O-ringReplace O-Ring 5Replace O-Ring Install new O-rings on