Broken Alternator bolt....

[legotech7]

Well the other day I noticed that my volt meter was reading a little under 12 volts,so I look under the hood and noticed that the bolt that holds the bracket under neath the alternator broke to where its bolted to the passenger side of the head on the engine..So I attempt to tap out the broken piece left in the head. I drilled a hole in to the broken bolt. ( That was no fun ) I tried to use an extractor to get the piece out, but I needed to drill the hole in further so I could tap in the extractor. I could get to go in as soon as I turned the the extractor it would just pop out. I tried to drill the hole another size bigger, but still I couldn't get it to come out. Anyone have any other Ideas as to how I can remedy this? It seemed so simple...but.... no.... Is there another type of bracket I can use that can mount else where? The alt. is mounted on the passenger side of the engine. I believe there should be more brackets attached to the alternator, but I'm not sure . I hope I didn't ruin that bolt hole!.....

The top pic is where my head ache is.. And the bottom pic is the bracket that is on there now. Maybe some can tell me how to use a different mounting point... Thanks one and all.......

[frednoah]

Several of us posted suggested fixes in the What did you do today thread. Have you looked those over?

[passthebuck]

My favourite bolt extraction method is to turn my mig welder up high & hold a nut with a vice grip over the hole that contains the broken piece. I then fill the hole with weld until it welds thoroughly to the nut. The heat usually busts the bond & when it cools, a bit of oil & it comes right out.

Second favourite is left handed drill bits. Drill out the bolt & eventually it catches & spins the remains out.

I can't tell just how deep the remains are from the photo but the mig technique is my goto.

[legotech7]

Thanks passthebuck, I did think about welding a bolt to whats left in that hole. I will try that if all else fails. I did use the left handed drill bits, but that remaining piece is stuck in the pretty good, didn't come out using that method.

Hope to get some more ideas...
Thanks again.......

[hamjet]

Boy, that looks tough. it looks like its drilled off center in the photo, plus I cant tell how deep you drilled. if you're off center you're going to keep going bigger on the drill size till you start hitting the threads on the one side.
i'm not sure how deep you can go, you should be able to feel it when you get through the bolt with a small drill bit. if you can stick a nail or something in the bolt hole on the driver side head back by the fire wall and mark it that will also give you an idea how deep it is. then you can probably start picking at it with a small prick punch and try prying to bend the sides of the bolt in. It also looks in the photo that the bolt hole is a little distorted, You might have to chamfer that.
do you have a torch? if so once you have the bolt drilled take the torch and move it around in the hole trying NOT to get the head threads red, but the remains of the bolt. then it will be easier to bunch up to get it out. WOW, its a lot harder explaining it than doing it. I hope it helps... OR, you can pull the heads and switch sides. then you'll have fresh new holes :>) You do have to go all the way through the bolt for it to work thow....

[legotech7]

Thanks hamjet, yes I tried to center as well as I could so it might be off center a bit. The hole size is 3/8'' with the thread being 16. I think I'm running out of options, other than what another member had suggested. To weld a bolt to the remaining piece and back it off that way. I wish I had thought of that before I started drilling, I'd have more of the remaining bolt left to weld to. Now I might have to fill it with weld and hope I don't weld into the threads. What a real pain in the ass this is turned out to be! The weather here has been really wet, and my truck is parked out side of my garage. Have another project in there and no more room to work in, so I might have to wait a bit to do this.

Thanks again for you suggestion, I really appreciate it. Keep em coming.......

[Lee H]

Looks like it is to far in to MIG. I would heat it up and then use a smaller bit and go in a little bit at a time until I got to the end. Once there I and see if a smaller easy out would work, then go to a slightly larger bit, etc. If the threads are buggered up or if they get there you will need to helicoil it.

[legotech7]

I posted a video on you tube, in hope of getting a little help with my broken bolt dilemma. Perhaps this can give a better perspective in trying to get some solutions...

Thanks http://youtu.be/83UBYtfUs4M
http://youtu.be/83UBYtfUs4M

[bigmac73]

I would get a burr /(rotary file) for a Pneumatic grinder(P grinder) and grind it out and, then drill a new hole for a Heli coil install

http://www.summitracing.com/search/d...l?keyword=burr

http://www.summitracing.com/search?keyword=heli%20coil

[legotech7]

Yes the heli coil option is being considered. Perhaps the last resort.......

[70CHEVYBB]

I have been removing broken bolts with a mig for 25 years. It is this simple make sure the area is clean, make sure you have a good ground, use a pair of needle nose pliers and hold a 3/8 nut over the center of the old bolt, push the mig nozzle up to the nut making sure the wire is pointed at the center of the broken bolt. drop your hood and pull the trigger, watch as the nut starts to turn cherry red from the head out as soon as its all cherry red stop. Take a small pair of channel lock pliers grab the nut while still hot, slowly wiggle back and forth and you will feel it brake free of the cast irno head and the just unscrew the broken bolt. you will not have to heat the head up. This works it may take a few tries depending on your welding skills.

[legotech7]

I don't know, 70CHEVYBB if you saw the pics or the vid, but there is no nut up flush to the head. As I mentioned before I tried using the left handed drill bits to back them off. They didn't work. So i tried to drill in further, witch got me deeper, to no avail. Still the nut is in there. I thought if I could use a long bolt and some tack it to the remaining bolt in the hole and hope it hold enough to back it off. I don't know...... If all else fails I will have to drill the hole clean and use a helicoil to repair it, and hope that works. Just waiting for the weather to let up.......PITA.................

[70CHEVYBB]

Please do exactly how I explained, It will come out. I looked at the picture and I have taken broken bolts out the look way worse the that. drilling a hole makes the weld stick even better.

[legotech7]

Thanks 70CHEVYBB, I will try as suggested. Wish me luck..lol......