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TR-7 Head Stud Removal

To: "bcr!en.ecn.purdue.edu!chad"@bellcore.bellcore.com
Subject: TR-7 Head Stud Removal
From: mit-eddie!bellcore.bellcore.com!taichi!whs70@EDDIE.MIT.EDU (W. H. Sohl)
Date: 15 Oct 1990 10:11 EDT
>
>Read you loud and clear in the Midwest.  I've no money for my Triumph now
>and am driving a Diesel Escort.  Bad looks, but GOOD mileage (48mpg)  Also
>I did this BEFORE the gas crunch!  I still want to hear Bill Sohl's
>TR-7 head removing story.  It took me a week of hell before I drove a
>wood cutting wedge between the head and block!!  The studs were SOOOO corroded.
>I even welded nuts to the top of them and broke them off!  FInally I
>decided the head had to come off even just to put on a new one!
>
>Chad

I'm posting this on blind faith that since the british-cars
list was still working last week (despite Jim M's departure
from alliant) that the list is still working now.

In answer to the TR-7 stud removal, I'll be brief since
I'm working on a full tech article for a forthcoming
VTR magazine.  To remove the studs from the TR-7, the
following sequence of efforts should be tried.  This assumes
that the lower 5 bolts have all been removed and, off
course, that the stud nuts are off.

1. First, inundate the studs with WD-40.

2. The studs have a screwdriver slot, try using that to
remove them (probability of success near zero).

3. Jam together two nuts on the stud to make it into a
bolt affair.  Do this with a box wrench in place on the lower
of the two nuts.  Try removing the stud.  This worked on
three of the five studs on my son's "low mileage" TR-7.

To increase the probability of this working, try and locate
nuts that are taller in height (that is they have more
threads in them) then the ones used on the studs.

4. At this point, the studs that haven't come out are your
major problem ones, most likely due to corrosion between the
stud and the aluminum cylinder head.  If you examine the stock
studs, you'll find the center of the slotted area to be
a small round opening.  I then used an air impact hammer
held in place (I used the pointed impact tip) against the
rounded center of the stud and hammered away at the stud in
an effort to "break-up" the corrosion.  In a very short time
I was able (using method 3) to remove the fourth stud.

The last stud was very corroded, as there was absolutly no
visible clearance between the stud and the hole in the cylinder
head.  I found that using the airhammer as described was
slowly breaking up the corrosion, so I just kept at it;
periodically flushing the stud with more WD-40.  I also
was able, with now only one stud remaining, to slightly rotate
the head itself.  The rotation of the head didn't free the
stud in the head yet, but it did at least "break" the hold
that might have been present between the stud and the engine
block which meant that the only thing preventing the stud
from turning was the corrosion.  Again, more use of the air
hammer, try to remove the stud (method 3), more air hammer,
try again, etc. etc. until I was finally able to begin turning
the stud.  (Note, each session with the air hammer was done for
about at least 10 minutes.)

In my case, once the stud began to turn it backed the head fully
off the block and I then had the cylinder head removed with the
stud still in it.  Since the stud did turn, I just kept flushing it
with more WD-40 and turning it until I felt it was free enough that
I was able to tap it out with a hammer and a punch.

5. Last option, not recommended unless desperation has been
reached after using the above.  Weld the two looked nuts to
the stud to form a bolt.  The problem with this is that you
can be affecting the hardness of the stud when you weld it which
can lead to the stud breaking off.  I think that given a source of
air and an air hammer, that the process used in 4. will work
for most cases, recognizing that you may spend several hours
with the air hammer doing its thing to break-up the corrosion.
The benefit is that you don't damage the head.

Well, this turned out longer than I expected, but I hope it
helps any other TR-7 owner out there.  IMPORTANT, when
reassembling, use new studs to replace the badly corroded ones
and do coat all the studs and bolts with a good anti-sease
compound.

------------------------------------------------------------------------
Bill Sohl                      ||  email
Bellcore, Morristown, NJ       ||   UUCP    bcr!taichi!whs70
(Bell Communications Research) ||    or
201-829-2879 Weekdays          || Internet  whs70@taichi.cc.bellcore.com
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