snap bolt removal
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Instructor
Joined: Feb 2004
Posts: 241
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From: Ravenna Ohio
snap bolt removal
I broke both of my trans mount bolts off in the trans case. I allready have them drilled and trying the extractor along with soaking PB blaster. Trying to be careful so i don't break the extractor. Any other ideas to try?
Advanced
Joined: Feb 2005
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last time that happened to me. Like exactly that cept was a mount for my fog pump on the intake manifold i just drilled out the exact same size hole. slowly moving up in drill bit sizes, and then i rethread it. But thats just me, and its because i was impatient.
Race Director
Joined: Oct 2002
Posts: 12,065
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From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
have ya tried to GENTLY & LIGHTLY heat the case around where the bolt holes are? A lot of times when you heat it, it will expand the metal and break loose the corrosion around them and you can then back them out.
Racer
Joined: Jul 2004
Posts: 286
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From: Mesa az
First make sure the drill hole is centered as good as possible. Then use left-hand drill bits, those that drill by rotating opposite to the normal direction. Start with a small size then move on up. The heating of the drilling and the twist of the drill will "back the broken bolt out". If the bolt can be taken out this way is the best.
Melting Slicks
Joined: May 2001
Posts: 2,131
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From: May help you? You can sure as hell try!
Definitely some heat will help! Especially with an aluminum case. I've heard of guys heating the area and then quenching the bolt with a shot of penetrating oil. This causes the bolt to contract away from the case because of the cooling and the oil to soak between the case and the bolts. Both good things.
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Race Director
Joined: Oct 2002
Posts: 12,065
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From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Originally Posted by john1977
Ok wattac2 tell this old guy where you get left turn bits,never knew there was such a thing. Think i need to add some to my tool set.
My grandfather had a bunch of them. They were ground differently than normal bits. I asked the metals tech and structures guys I work with about them and you would have thought I was talking Greek to them!
Burning Brakes
Joined: Apr 2000
Posts: 1,076
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From: Dixie TN
Originally Posted by wattac2
First make sure the drill hole is centered as good as possible. Then use left-hand drill bits, those that drill by rotating opposite to the normal direction. Start with a small size then move on up. The heating of the drilling and the twist of the drill will "back the broken bolt out". If the bolt can be taken out this way is the best.
Instructor
Joined: Dec 2004
Posts: 198
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From: Newmarket Ontario
If all the suggestions that have been posted fails the one thing left to do is to take out the unit and have the bolts edmed out. This is a electro discharge machine that uses a copper electrode slightly smaller than the bolt. The electrode thru electrical current burns the bolt away and you then pull the remainder of the threads away with a pair of needle nose pliers. Most machine and tool and die shops would have one.
Melting Slicks
Joined: Jun 2003
Posts: 2,490
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From: A high school diploma fixing what a college degree broke TN
St. Jude Donor '03 thru '26
Originally Posted by john1977
Ok wattac2 tell this old guy where you get left turn bits,never knew there was such a thing. Think i need to add some to my tool set.
Thread Starter
Instructor
Joined: Feb 2004
Posts: 241
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From: Ravenna Ohio
Well it happend. I was heating and quenching with penetrating oil and the extractor snapped in the hole. This sucks. I have to go to the shop tommorow to pick up my block so i will see what they can do.
Racer
Joined: Jul 2004
Posts: 286
Likes: 1
From: Mesa az
Now that the hardened extractor is in the hole move on to a drimel cutter bit, a small one with a "ball" style head. I've had good luck grinding out the extractor and the bolt. If you're real careful most of the bolt will come out before you start cutting into the threads. I've also cut through one side of a bolt, completely through the threads, after grinding out most of the bolt, then use a small sharp chisel to "unwrap" the remaining parts of the bolt out of the hole. You'll probably have to clean up the threads with a tap. Takes time.
Good luck, been there, done that, several times.
And, as some of the previous posts indicate, left hand drills are available at most better machine supply houses. And if you get them keep them separate from all your other bits. Its real fustrating trying to drill with them when you have the drill rotating in the normal direction. Lots a heat and smoke, but litte action. Like I said, been there, done that.
Good luck, been there, done that, several times.
And, as some of the previous posts indicate, left hand drills are available at most better machine supply houses. And if you get them keep them separate from all your other bits. Its real fustrating trying to drill with them when you have the drill rotating in the normal direction. Lots a heat and smoke, but litte action. Like I said, been there, done that.
