Originally Posted by Earthman
JB Weld isn't nearly as strong as cast aluminum (see attached typical properties of AL vs JB Weld). However, might work in some applications as a filler in a confined space, but not with heavy or repeated loading; i.e., vibration. In any case, I agree with removing broken stud(s) and replacing.
JB Weld's website: J-B Weld Company - J-B WELD Product Information
thanks for that info, brings a fresh light into my eyes