electric dryer was rumbling - wheel or belt?

Unplugged dryer. Front came off easily. Removed front of blower. Wheel came off fairly easily - could then see that shaft of motor was circular with flattened side but inside of old wheel was rounded. New wheel popped right on. Took tumbler off so I could clean lint out more easily and get a good view of how the belt threaded through. Put the tumbler back on and reached back with both hands to thread it. Took a half dozen tries until I was sure it was seated correctly and not twisted. Put front... of dryer back on. So far (a week or so) the rumble is gone. Seems blower wheel was the cause of the rumble. Belt didn't seem worn but replaced anyhow.