2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 155Get this manual
FINAL DRIVE AWD Diagnosis
Symptom: AWD Will Not Engage 1Check the gearcase coil resistanceTo test the gearcase coil resistance, use the coil harnessThe gearcase coil should measure between 21-24 Ohms and at 68 (20 C)BNWH to GY
Check to make sure the coil is seated in the U-shaped insert that is pressed into the gearcase housingThe top of the coil should be seated below the U-shaped insertThe U-shaped insert controls the pole gapIf the top of the coil is above the surface of the U-shaped insert it raises the armature plate, thereby increasing pole gapIf the pole gap increases the coil will not be strong enough to engage the AWD systemSide Cutaway View of Gearcase Cover Coil
U-Shaped Insert