I have a 2008 mustang 4.0, it's a daily driver only mod is BBK intake. Some how while making a turn from a stop the threads to my harmonic balancer were ripped off off the engine and fell into the street, this is not a race car I don't drive it like one. Any thought on how or why this happened so I can prevent it. Literally the threading separated from the pulley and my serpentine melted to the remains of the harmonic balancer. The only signs I had was a minor speak this morning that I thought was my belt but stopped after the car warmed up.

 

Unless I am mistaken , the pulley on those engines is an integral part of the balancer. There is a rubber damper between the outer pulley and inner balancer. Most likely the pulley became separated from the rubber , this is a common occurrence on the older mustangs as the rubber gets dried and brittle, but I don't know on the 08s.
Worst case you need a new belt and a new balancer/pulley assembly.

 

I'll know more when I get it home but from what I saw metal was actually torn it wasn't a clean break

 

get some pictures of the damage posted up on here.

 

Welcome, I'd love to see pic's of this also. It would have to be a manufacturing defect. But one I've never seen.