This is a very common problem of semi-automatic washing machines. The machines often shake or wobble too much while the spinning process. This happens because the clothes do not get distributed evenly. When the load is more at one side, the spinner faces difficulty while spinning and wobbles too much. You can avoid this problem. Do not make a pile of wet clothes. Put the clothes into the dryer one by one. And also spread them into the whole dryer. Do not dump them at one side only.
This will help you to avoid a shaky spinner.