[200q20v] Tech report: Broken Stud removal
QSHIPQ at aol.com
QSHIPQ at aol.com
Sat Mar 10 12:44:53 EST 2001
The MacGuyver victronics silver cross award goes to....
.... Jeff Goggin today for the stud removal procedure he's posted over the
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.
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.
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
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
* 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.
Stud removal specialist emuritus
QSHIPQ Performance Tuning
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