on my polaris when i am in turf mode and i make a hard turn going about 15 mph i hear a squeal noise from the rear could this be the adc tring to work

 

I don't think it's the ADC. In turf mode only the outside tire should be engaged.
(outside of the turn) The inside tire should be disengaged (coasting). it could be that the diff. fluid is low or dirty or it possibly even has the wrong fluid in it.

Welcome to the forum hvychevy!