Bravo Range

I was given a Craftsman 10” band saw recently. It’s pretty old but not in terrible shape. The blade continually slides off the bottom wheel. There are 3 wheels in total. Doesn’t matter how much I adjust the tension. The blade guides seem to be right where they should. I don’t know what else to do. Maybe time to replace the tires? Like I said it’s old. Wheels don’t seem to be wobbling but the blade continually slides off that bottom wheel.