Squealing noise when dryer turns on

Hi Jake/all - well, this dryer wants some more attention from me I guess. Everything is working fine, but when it starts up there is a very noticeable squealing noise, somewhat pulsing (louder - softer - louder...). Now I am going to guess one of the wheel bearings is starting to go, but thought I'd ask here first to make sure I shouldn't be looking for other things (drive motor? other?). After it runs for a while the squeal subsides if that indicates anything.

Thanks!
David