
11-06-2011
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Senior Member
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Join Date: Oct 2010
Posts: 551
Rep Power: 2
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Get the other bolts undone, even if these are also broken off in the process. You have to get a drill to the broken bolt. I have had bad luck with the Easy-out. These are made of hardened steel and if broken off by being too agressive, are impossible to get out, cannot be drilled into. You have to buy a new casting at that point. I have seen nice results with the left hand drill. Just drilling through the center of a bolt seems to release some of the holding power, maybe the bolt shrinks a little and the bolt spins right out when you are two thirds the way through. However; what I usually do is use a small drill, say about one quarter the diameter of the bolt, use a prickk (drop one of the k, the censor for postings didn't like the word with one k) punch to make a point directly in the middle of the bolt, and drill down through the length of the broken off bolt being very carefull to stay in the center. I then use a larger drill that is the diameter of the bottom of the threads and drill using the smaller hole as a pilot to keep the larger dill centered. A pick then can be used to scrape out the remainder of the bolt thread. If you muff the procedure, you can drill it out to an even larger hole, use a special tap for a Heli-coil, and have threads stronger than the original. If all of this sounds a bit much, take it to an automotive machine shop and have them do it. It's something they do all the time and get very good at it.
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