Whirlpool 3rler5437kq0

I have no experience with these dryers at all. I had a look yesterday and removed front lower panel to reveal that belt was snapped. I noticed that when machine turned on the motor spindle will not turn. It may be a silly question but can the motor detect the broken belt and shut down. Looking at pic of new motor there seems to be some kind of extra collar on spindle Timer clicks away only when start button held in. all stats are ok. Paul