Rick,

I am not familiar with the 2B however I have found dial cords tend to
elasticize with age, stretching instead of driving the pulley assembly. If
the 2B uses a pulley/dial string arrangement you may fix the problem by
simply replacing the dial cord. I've experienced the same backlash effect
but it was remedied with fresh string.

I am almost embarrassed to suggest my other "fix" for the problem. Make
sure the skirt for your dial knob isn't rubbing the front panel. I'm sure
you've already done that and forgive me for suggesting otherwise.

Good luck.

W9STB