Does anyone want to speculate what this could be, before I get the transmission out? The belts are still connected to the crank and the crank is not spinning.

http://www.youtube.com/watch?v=jGNUXGwMqfA

 

Wow, that's the flywheel spinning freely. I wonder if you sheared off the splines on the crank shaft.

 

ah... thats definitely not good.

 

Probably broke the flywheel bolts and the input shaft is holding the whole assembly in place. Put the trans in gear and see if it spins.

 

Just curious, how about divulging the details of how this happened?

 

Yea whether in neutral or in gear you shouldn't be able to freely rotate the flywheel because of engine compression, so I would say your flywheel has somehow disconnected from your crankshaft I would take a wild guess that the rattling you hear when rotating the flywheel are the bolts that use to connect the flywheel to the crankshaft.

 

+ 1 either way flywheel is not connected to the crank.. broken bolts , crank split right by the last main bearing cap. stick a pry bar in there and see if u can push the flywheel towards the tranny.