Sony TC-277 slows down
I have a Sony TC277 that slows down after about an hour playing time.
I have read on other forums that it was the idler wheel wore out, but I don't think that is the case.
I have cleaned and lubed the recorder, and cleaned all rubber wheels and belts.
The tension is not too tight,,the tape flows freely through the heads at the right speed for about 45 minutes, then it slows down.
I can turn the recorder off until it cools down, and it plays the normal speed.
Has anyone had this problem with A sony tape deck? Any help would be appreciated.