My fan is making noises like a canary but otherwise works fine.
Occasionally the noise goes away in other settings but then comes back.
I suspect a dry bearing.
Can it be lubricated or does the whole shebang have to come out?
I had a 76 245 once where the heatercore leaked and the mechanic suggested to replace the whole fan motor while at it. He claimed it was a nightmare. Cost me a bundle too. Must be a stinker because normally the mechanic says: No problem and then charges you. Here he was not keen on doing that kind of work.