First, make sure the bolt is actually stripped all the way down into the hole. To do this, make SURE the bolt head is cleaned out. Use a small screwdriver and some WD40 to clean out the head. Then put your allen socket into it, and tap with a hammer to make sure it's completely seated. Try again and see if it will grab the allen head now that it's in deeper.

If that doesn't work, the 12-point socket (as mentioned earlier) works for me all the time. Get one that is just slightly too small for the bolt head. Pound as hard as you can with a hammer until it seats on the bolt head. Spray with a ton of PB blaster (1/2 hour apart for a few hours works wonders if you have the time!) and unscrew. You'll be amazed..

Neal

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