The through-bolt on my alternator has worked itself out, causing the belt to be too loose resulting in a screeching noise when starting the car. But I cant get that bolt all the way back in. It goes about 4 inches in but just wont thread the last inch. Any suggestions? I think the hole might be full of grease and dirt blocking the bolt from threading in. What do you think? Any tricks to this? Tomorrow I will get in there with a wire brush and clean it out and try it again.

 

get yourself a tap an die set and retap the screw holes with the origional size tap