In some cases, you can also just retap the threads...if they are not drastically stripped right out, the size is M8 x 1.25 thread pitch...Otherwise it is just as Wrench said, helicoil it, do NOT try JB Weld or epoxy, it will not work for very long at all.
Moderators Note:
There were two threads on the same subject by same OP...I have merged them into one thread as there is no need for duplicate threads on the same subject which just results in duplication of effort for people to help out with the problem.