Originally Posted by Army

Doesn't sound so good if you got bits of old thread falling out - it sounds like you'd need to make the hole larger for a repair to work.

You mention that the old threads are probably an insert - that may be true but the screw hole could be made from a different metal such as an aluminum alloy. I DON'T KNOW THIS FOR SURE I'M GUESSING - as you often get that kind of effect from stripped threads in these light alloys.

A picture would probably help if you can take one. If not perhaps a parts diagram can confirm if the thread is indeed on a separate insert...