Re: The Mechanics Worst Nightmare!

[Bob Brooks <rbrooks@domain.elided>]

John:

If you can get access to the back side drilling a small hole and using a punch
to drive out the extractor is not a bad idea.  You then may be able to collapse
the bolt into the hole you drilled for the ectractor.  Or if not make the hole
bigger until the wall is thin enough to collapse.  If the hole is centered this
should not damage the threads in the original bolt hole.

If you are planning on bringing the block into a machine shop anyway, you may
want to have them add the extractor/bolt removal to the other work they are
going to do .  of course that is the easy way out.  I tend to go at things the
hard way, so I would remove the bolt first and then bring it in.  But that's
just me.

Bob
rbrooks@domain.elided

John A. Landry wrote:

> OK Gang, I could use some suggestions...
>
> This past weekend while tearing down the V392E I purchased from a local
> wrecking yard, I managed to snap off one of the water pump housing mounting
> bolts about 1/16" from the front face of the block.  The bolt is 3/8"
> course thread and is in a blind hole.
>
> I center punched the remains of the bolt, drilled it completely through.  I
> felt I did a pretty good job of getting the hole centered and straight, so
> everything was going good so far.  I then drove in a Rigid brand broken
> bolt extractor which measures 1/4" OD.  This type of extractor has splines
> which run lengthwise to engage the inside of the drilled hole.  A special
> nut then slips over the outside of the extractor protruding from the broken
> bolt, where it is turned to hopefully remove the broken bolt.
>
> I tried working the broken bolt back and forth with no luck.  I tried a
> little more force and *snap*... the extractor broke about 1/8" from the end
> of the broken bolt.  It broke in such a way that I cannot get a vice-grip
> on it to attempt to pull it out.  So now I have this super hardened
> extractor in the middle of a super stuck broken bolt.  I've had this happen
> before and always lucked out and somehow managed to get the extractor out.
> This time it looks pretty hopeless.
>
> In retrospect, I know I should have tried to weld a nut onto the end of the
> broken bolt, but that's hindsight.  What I'm looking for is suggestions on
> how to deal with the situation I'm in.
>
> I've had a couple of people suggest I try super heating the broken
> extractor with an acetylene torch to anneal it, making it possible to drill
> it out.  This might work but sound difficult.  The heat would have to be
> incredible to get the extractor that hot (when tightly surrounded by a
> heavy engine block).  Then I'd probably need a tungsten carbine drill, and
> doing this with a hand drill, I would have great fun trying to keep the bit
> on the extractor instead of walking off into the softer surrounding metal.
>
> I've also been told I can't expect to weld something to the extractor in
> order to try and pull it out with a slide hammer, so that's out.
>
> I was also warned against trying to weld a nut to the end of the broken
> bolt with the extractor still sticking out.
>
> So here's and idea I thought of this morning...
>
> I do have access to the opposite side of the block wall behind the bolt
> hole.  I was thinking I could drill a small hole through the backside of
> the block wall (say 1/8" ID) into the bottom of the blind hole, so I could
> insert a punch and drive out the broken extractor.  The backside of the
> block wall is right under the valley pan, and I don't see what harm having
> a small hole there once the water pump housing mounting bolt is there.  I'd
> probably fill the small hole with JB Weld or something anyway.
>
> So if that idea worked, once I get the extractor out, then what do I try?
> I mean this bolt is not going to move?  I'm afraid that trying to weld on a
> nut to what remains of the broken bolt will be fruitless.  As I mentioned
> in the beginning, the broken bolt was only sticking out 1/16" and now I've
> been drilling on it.  All that remains is a thin wall of the bolt.
>
> If I get the extractor out, I suppose I could let a machine shop mount the
> block in a mill/drilling machine and drill out the hole exactly on the
> enter and insert a new Helicoil.  I can't do this at home because I can't
> insure the new hole I'm drilling is properly centered on the original hole.
>
> Any suggestions on how to deal with this problem would be most appreciated.
>
> Regards,
>
> John L.
> --------------------------------------------------------------------------
> jlandry AT halcyon DOT com    | "A fear of rebuilding automatic
> Conservative Libertarian      |  transmissions is a sign of retarded
> Life Member of the NRA        |  sexual and emotional maturity."
> WA Arms Collectors            |                          - Sigmund Freud
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> Commercial Helicopter - Inst. |                   to Mechanical Analysis"



--
Bob
rbrooks@domain.elided

Micrel, Inc.
http://www.micrelinc.com