I have been trying to teach myself clock repair for some time now but one thing the books and videos have not helped with is how much movement in the escape wheel is too much. Case in point I have just cleaned and repaired an E.N. Welch which runs strong with out the crutch installed but will not run with the crutch I now their is movement in the bushing of the escape wheel and wonder if I should re bush the movement . is their a rule of thumb on when to replace these bushings? Thanks Carl.