2007 Polaris Sportsman 700/800/800 X2 EFI Service Manual, Page 287Get this manual
Sportsman X2 Transmission 6Inspect the shift drum for any damage or wearInspect the splines of the shift drumReplace the O-rings on the end of the shift drum and lubricate them before assemblyNOTE: To ease assembly use plastic tie strap to hold the shift forks (D) and the shift drum (C) together during assemblyC
Stretch the silent chain on flat surface and measure the length of pitches in minimum of three places on the chainReplace the chain if the measurement is longer than the service limitWith the gearcase on it's side, hold the gear cluster assembly and output assembly togetherCarefully install each shaft into their respective recess in the gearcase