What's the best way to tell if you have the right tension on your alternator belt? I replaced my belt 4 months ago and made a tick mark off to the side to annotate where the old belt tension was that way I didn't have to mess with it. Well when I put on the new dayco belt and tightened it up to that mark that I made it seemed a little tight so I loosened it down. I took my car into the shop a couple of days ago to get an oil change and they said the belt was kind of squealing, so they adjusted it for me, and they brought the tension up to the sharpie mark i made. How can I tell if it has the 1/4'' of play in it? It feels a little tight. do i push up and down on the top or on the side?