Twisted-off Spark plug Threads Removed

A mechanic twisted off #7 spark plug on my '96 Dodge Ram 1500, 5.7
Liter V-8. (Furthest back on left, and obstructed by master cylinder,
vacuum chamber, steering column, and several brake-lines. At least
it sloped forward, instead of rearward). He then sent me on my way to
have it dealt with somewhere else. And, yes, it was a Champion plug
as has been criticized by some on the web (RC12YC)..14mm, 3/4" reach.
I wasn't quick enough to challenge him when he used only a simple
ratchet handle and socket, which exerts extra side-pressure on the
threads, and a harmful side-tilting force on the plug. He ovbviously
should have used an extension, using any method to insure that the
extension only exerted pure "rotational force" on the spark plug.
He had advised against using an impact tool on it.
In fairness, I had removed the other 7 plugs and another one was
extremely tight, and I had thought it might twist off. I took the last
one to the mechanic because I thought he might have some better method.


Some of my initial ideas for removing the threads failed, wasting
a period of time ..(lucky I didn't need the truck)....including a few
careless maneuvers that cost me a lot of wasted time and
effort...especially because of waiting almost a day every time I used
JB-Weld epoxy that needed to cure. It's possible some of my attempts may
have helped a little, BUT HERE IS WHAT FINALLY WORKED: (based on a web-
poster's success using an oxy/acetyln torch for heating).


I bought a "square-type", tapered bolt remover (usually called Easy-Outs)
sized for 5/16" hole. Then bought a can of some kind of "freezing
spray" at Radio Shack that can chill to -50 degree F. (Also available
at www.mcminone.com "Envi-Ro-Tech Freezer" #20-2200, 1-800-543-4330
or 1-877-626-3532).

I then went back to the mechanic and he used
his Oxy/Acetlyn torch with a very small tip to heat the the
remaining spark plug shell to a cherry- red. I then immediately sprayed
it with the cold-spray, after which he was able to use the square
easy-out to remove the remains of the spark plug. (Actually, we repeated
the heating, chilling sequence a second time). He admitted that he had
never been able to get them out before and had initially sent me away to
a machine shop when he first broke it off. I, of course, got my
suggestions from posters on the internet.

In hindsight, I might try an alternate approach first: I bought a Left
Hand thread tap (3/8"-16) that can be hand-turned thru the existing hole
(strongly magnetized to retain the metal particles...the shell spark gap
electrode only bent, it did not separate and fall into the cylinder).
This provides two things...it thins, or weakens the shell a little, and
when a left-hand thread bolt is screwed in, it bottoms out
counter-clockwise after which force is now applied to turning the plug
shell out....without any outward pressure to the sides, such as a tapered
square easy-out must have (heating cherry red as before). Unfortunately,
I only thought of this after I had earlier run a right-hand tap
through...and as I suspected the threads were too weak to avoid stripping
out. I was only able to buy a grade 5 bolt strength (left-hand), so a
judgement would have to be made, whether it would twist off. Of course
we had the same worry with the tapered square easy-out.
....so it's possible my earlier misadventure cutting the threads, did help
in the final success.

Needless to say, I used Anti-seize paste on the threads, although some
claim that changes the "heat-range" value.

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