ADC question

I have an 08 500 HO and was wondering if anyone could tell how this works and how it would effect the 4wd? I am getting a real rough vibration, jumping feeling in the front end on decel but only in ADC 4wd but not in regular 4wd. Was thinking it was the cage but not sure as it only seems to be happening in one but not the other. Any help would be appreciated.