tranny drain bolt thread size

[4doorboost]

does anyone know the size of the bolt, i think its an m17 thread but not sure i know its a 24 mm head but whats the thread size, thanks

 

Should be 18mm X 1.5, IIRC. Easy way to check is if an old O2 sensor will screw in, all O2's are the above thread.

 

[4doorboost]

so the reason i asked is cause the threads in my tranny stripped should i helicoil it and use the same bolt or tap and go one size bigger? thinkin just helicoil so i can use the same bolt