I got a Cub several years ago that was already used and abused. It was darn near impossible to take off without just slamming the throttle and trying to make corrections until it was up. I took the wheels off and put a straight edge across both axles. They were off from each other and also off from the centerline. I spent some time with a couple pairs of channel locks getting the axles both perpendicular to the centerline of the plane, then got the tailwheel adjusted to roll straight. Since then, it has a straight roll with no tendency to yaw when the tailwheel lifts, then a slight and very predictable left turn tendency as I rotate to takeoff. The time spent getting the gear perfectly straight was well worth it.