Originally Posted by JohnDThompson

The axle bends almost always at the drive side bearing. Remove the freewheel and note how the axle is bent. Insert the axle into an axle vise as close to the hub shell as possible. Using the rim as a lever, bend the axle back into alignment. Remove from axle vise and check for straightness by rotating the axle in the hub and looking for wobble. Repeat as needed.