How do I fix bandsaw-blade wobble?

I loved your online video about how to tune up a bandsaw. I followed all of your steps to the letter. However, my bandsaw blade has a back-and-forth motion. What's causing this and how do I correct it?
—James Mulholland, Romulus, Mich.

If the blade was welded even slightly out of square, it would show up as the back-and-forth motion that you describe, James. Remove the blade and replace it with another. If the problem goes away, call the blade manufacturer or the retailer where you purchased the defective blade, and ask for a replacement.

If the problem persists, check the tires on the wheels. The blade on a saw left idle for long periods of time can leave an impression in the rubber tire which might cause erratic tracking. Purchase and install aftermarket replacement tires. (Search for "bandsaw tire" at woodcraft.com.)

If you still see a back-and-forth motion, the culprit is probably the wheel itself. A bad bearing or a bent shaft warrant a call to the manufacturer who can direct you to the nearest service center.