[s-cars] broken stud removal tools

[Marc Swanson]

> I could not open the site to see the extractor, but can tell you from 
> experience that very few extractors work well in a very few instances. The problem 
> with them is that to work, they must wedge into the center of the broken stud. 
> The wedging action usually exerts enough pressure to make it even more 
> difficult to remove the stud.  

Yeah, I know what you mean.  I've had the best luck with the straight
flute style extractors but no luck this time around.


> It is best to remove the stud without wedging.  The simplest way with least 
> risk to the precious head is to take it to a machine shop and have the stud EDM 
> machined out. Many shops have a tool called a 'Disintegrator' which will burn 
> out the stud without damage to the threads (a helicoil is still a good idea). 
> This will cost, probably about $30, but there is no risk.

That would be fine, except I really don't want to have to remove the
head.  I want to try to get the car up and running by friday night and
that would add a whole level of unnecessary complexity to the job.


> If you favor the do-it-yourself route, then I prefer the following:
> 
> Obtain a nut, one size larger than the nut used on the stud originally.  
> Place the nut over the broken stud (stud can protrude, be level with, or be 
> slightly below the head surface) and weld the nut to the stud. You can stick weld, 
> mig, tig or gas weld, I've done it with all methods.

I wish I would have started with this route.  there was a small nub of
the stud protruding from the head.  I foolishly wasted the opportunity
by starting off trying to drill a guide hole down the shaft of the stud
to use the flute extractors.

After that failed I tried to build up a nub of weld onto the broken
shaft but there just wasn't enough material by this point to build a
bead on.


> The heat from welding causes the stud to attempt to expand in the head. Upon 
> cooling, the stud will contract and help loosen it's hold to the aluminum.
> Allow all to cool, then remove carefully.  Usually a stud in aluminum will 
> grab and gall on the way out and get stuck again. It is necessary to work the 
> stud back and forth a little at a time, making sure to keep it loose. Too much 
> force will stick it and gall and it will break again for certain.   If it 
> breaks again, go to plan B.
> 
> I've pulled hundreds of studs from exhaust ports on air-cooled aluminum 
> cylinder heads. While the nut-welding trick works about 3/4 of the time, I usually 
> just mill them out because I want to install a helicoil anyway.  

Yeah, at this point it looks like the helicoil will most likely be
necessary.. but who knows.  Maybe I'll get lucky..

Wish me luck, I'll need it!

-- 
-Marc Swanson-
95.5 //S6 Avant
87 4ktq
88 90q
www.mswanson.com/audi