This dryer had been making a squealing noise when starting for a little while. Today it stopped tumbling all together and now just makes a loud rattling or rumbling noise when turned on.

I've removed the drum and inspected the rollers, belt and idler pulley. The pulley definitely needs to be replaced but the rollers and belt look okay, although I'll replace them anyway since I have it all taken apart.

The one thing that concerns me, however, is that the threaded pulley on the motor shaft turns freely. If I turn the motor manually the pulley turns with it unless I hold on to it. I can also spin the pulley without turning the motor. I've looked to see if this is a replaceable part and it looks like the entire motor has to be replaced. Is this a part that can break free from the motor shaft and could be the cause my issue? If it's broken, can it be replaced without replacing the entire motor?

Thank you in advance for any help.