2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 159Get this manual
FINAL DRIVE 12Inspect the output hub bearings (arrows)Replace bearings if wear or damage is found14Inspect the magnetic coil (I) in the output housingTest the resistance of the coil using an ohmmeterReplace case half if coil is found to be non-functional or if the coil surface is damaged
I NOTE: Due to extremely close tolerances and minimal wear, the bearings must be inspected visually, and by feelWhile rotating bearings by hand, inspect for rough spots, discoloration, or corrosionThe bearings should turn smoothly and quietly, with no detectable up and down movement and minimal movement side to side13Inspect the armature plate (E) for consistent wear patternUneven wear of the armature plate surface (E) indicates warped plate, which may cause intermittent operation