Can anyone tell me the maximum and minimum diameter a towball should be, I have some indentations in my towball and would like to dress them out so would like to to know these dimensions.
The lower wear limit for a 50mm tow-ball is 49.61mm - that should cause an AL-KO coupling head to show red for a worn tow-ball - and should then be replaced.
I'd also be concerned that you could keep the tow-ball spherical if you dress it and not introduce low spots - that would either negate the usefulness of the friction stabiliser - or cause it to jam...