2009 Polaris Scrambler 500 4x4 2x4 factory service manual, Page 188Get this manual
TRANSMISSION 7Remove output shaft and gear assembly along with sprocket and chain, by tapping on shaft with soft faced hammer, from the back side of the gear case
10Inspect shift fork surface for wear or damageReplace if necessay8Remove roller chainNote position of sprockets and gearStretch chain tight on flat surface and measure the length of pitches in minimum of three places on chainReplace chain if measurement is longer than 5.05 (128.27 mm)Measure pitches