Im unsure anyone will know the answer. i have a 1973 Ford pickup AM radio and I cant move the tuning shaft. There are plastic gears so Im not wanting to force anything. Where would this be stuck? The shaft? The gear? And what do I use to loosen it? Ive never worked on an auto radio before so its new to me. See pics for what Im dealing with. Thanks!

It's probably metal to metal corrosion sticking it. I think if you remove the C clip on the shaft of the big gear you can separate the 2 gears to safely check which shaft(s) are stuck.

If it's metal to metal corrosion or petrified grease a penetrating oil like PBlaster should be able to unstick it.

Thanks! I'll take a look at it in the next day or two and get back. Its not a rush thing, I just dont want to break it.

It ended out I didnt need to remove any clips. I loosened the nut on the outside of the radio (on the shaft) and that must have taken the pressure off of it as it turned then but hard. Then I just kept adding 3 in 1 oil into end of shaft while I turned it back and forth. So its all fixed, the shaft anyway. Thank you again for your help.