I am thinking of giving the oversize drain plug a try. I found that plug is M12 size, but I have seen three types M12-1.25, M12-1.5, and M12-1.75. I think that 1.25, 1.5, 1.75 refers to the distance between threads. So, the question is which thread size will be better to fix the problem?
Thanks for all your suggestions in advance,
S.B.