Tech report: Broken Stud removal

[QSHIPQ at aol.com]

The MacGuyver victronics silver cross award goes to....
....  Jeff Goggin today for the stud removal procedure he's posted over the 
years

After reading Jeff's posts a few times wrt using a welder and some vice grips 
to remove broken studs, I decided to try the self study course.  I did a 
total of 16 (between 5 heads in my shop yesterday, the last for the actual 
customer car).  After some practice, I'm now confident that the absolute 
worst studs (totally crudded head, 1/4in recessed stud) can be extracted via 
this method, leaving a perfectly clean intact and new looking threads in the 
head.  All studs, from *all* heads came out using this method.

The procedure:
Using a welder, slowly build up a bead of weld on top of the stud, until it 
clears the surface of the head.  Using vice grips, grab the weld and twist 
out the stud remains.  I used an oxymig at the slowest wire feed, and a 
medium high setting (110v 30amp welder) - ground clamp to the #1 cam journal.

The patient:
85 5k fwd, warped exhaust manifold popped #1 and #2 upper and lower studs.  
This car already had the upgraded studs and washer/nuts found on the later 
turbo cars.

The problems I encountered:
On a couple of them, the weld would break before the stud would break free.  
I just kept going at it, rewelding until the stud broke free.  Some times 
this took over 6 applications of the weld bead technique

Suggestions I found worked:
*  On one of the studs, I found that someone had overtorqued the stud so that 
it ruined the top threads of the hole.  I used a drill bit and opened up the 
hole a bit until it had slightly cut the top threads.  Then rocked the stud 
back and forth (applying some WD) until it cut it's way out of the top threads
*  Another stud I found was really in the head solidly.  After 6 repeated 
attempts, I drilled two holes and made a slot in the top of the stud, then 
did the weld technique again (effectively welding a screwdriver tip into the 
stud).  
*  Yet another stud broke free (finger tight) just by applying the first weld 
bead to it (adding credence to Jeff's surmise that the effect of the weld 
electrolysis itself loosens the bond between the two materials)
*  Using a hammer on the top of the bead each time, I tempered the bead, 
which appeared to reduce the chances of shearing the bead off the stud.
*  Allowing each bead to cool before adding more material, is the key to 
getting this right.
* I used the slowest wire feed setting on my welder (mig - med high amp 
setting)  basically dropping weld beads onto weld beads.

As this was my first attempt at this procedure, I took the easy route (85 5k 
fwd) and pulled the head to get the studs out on the customer car.  I have no 
doubt that this procedure can be done in the car, it's just a tougher job, 
and if number 4 or 5 is toasted, bigger than just removing the head itself.

I found that someone had been in this car before, and didn't shave the 
manifold, and it was really not flat.  Don't replace the studs if you 
*aren't* going to get the manifold machined, or you will be doing the project 
again really soon.

This procedure negates *any* need for the drill and helicoil procedure even 
the dealer uses.  The biggest problem with the drill and helicoil is getting 
a straight hole, and not going thru to the water jacket beneath.

Kudos Jeff, I'm a believer, the "knife" is yours sir.  I tried calling Jeff 
yesterday, but didn't get him, so I called Lawson and shared the awesome nerd 
btdt.  This procedure beggers belief until you give it a try....  From a 
customer perspective, I doubt this procedure is any *cheaper* in terms of 
actual time/cost, but it certainly is the right and better way to fix this 
common audi malady.

HTH

Scott Justusson
Stud removal specialist emuritus
QSHIPQ Performance Tuning
Chicago IL