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Stud problems

Ok, using oxy/ace torch. I have this one stud that giving me hell. Should i heat in the same area described in the rebuild book or around the outside of the case? I ask because in the book it described using a propane torch, not sure if it makes a difference. Plus there's a hazy oil residue left in the case that i don't want to mistakenly light on fire or something.
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Old 08-06-2003, 07:40 AM
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Fast,

I used the propane torch as described in the book. It worked on all but one which had to be taken to a specialty shop. I did have a guy try to use an arc welder on the stud, to no avail. Oxy/ace gets very hot but I seem to remember others doing it.
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Old 08-06-2003, 09:46 AM
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Just completed this on my 2.2 project due in part to Groesbeck Hurricane's generacity in loaning me the proper tool. Caution, heat the stur up at the base until just about red, but wait for it to cool slightly or you will distort/bend the stud. Ask me how I know...
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Old 08-06-2003, 09:53 AM
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1fast,

Once you get the targeted area hot (I didn't heat anything up)and you still have problems, other than taking the case to the shop to drill it out, I used my angle grinder to square off the stud, then with the biggest adjustable wrench I could find I cranked with slow, steady pressure. You may have to have your kid (or whomever) keep the case and stand from moving. It was scary but finally, snap, crackle, squeal and pop, all of them came loose... Good Luck!
Old 08-06-2003, 10:02 AM
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The thing is i didn't heat the area nearly as hot as you guys described. When heating the stud area, i only needed to heat on the average, about 4-5 seconds in order to get the stud to start coming out. I was actually more curious on heating inside the case bore area because that the only thing that i haven't tried yet.
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Old 08-06-2003, 12:32 PM
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Just to throw this in, i wanted to test and see how well the aluminum case acted as a heat sink. So i heat a specific area on the block for about 10 sec, then counted to 3 mississippi and touched it. To my surprise it was barely warm already getting cold. I should be ok with the torch cause i'm only running 7 psi through it and i'm using a welding/heating tip, not a cutting tip.
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Old 08-06-2003, 01:33 PM
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Hmmmmmm, I've been mentalling mesaging the idea of grinding the stud into shape for a large adjustable wrench. Only thing that bugs me is the fact that the one stuck is a dilvar stud, and i'm not sure if it'll get brittle and crack if i were to grind it down. Anyone ever try welding a nut onto the stud before?
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Old 08-06-2003, 02:05 PM
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heat the case in the cylinder bore, next to the stud, not the stud. there's a ton of info on this if you search the archives. use oxy/acet for best results. the case is a big heat sink, so chances of doing any damage to it are slim. i never killed one in 30 years.
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Old 08-06-2003, 04:23 PM
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Right - the cases are indeed very, very, very big heat sinks. Especially the aluminum ones (the studs really only break in the aluminum ones, so you wouldn't normally use a torch on a mag case). You can place a propane torch on an AL case for about 15-20 minutes, and it will just about get hot then. You can't do much damage with the propane. The oxy torch, however, you can indeed get carried away with. Use your head - don't do anything stupid...

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Old 08-07-2003, 01:19 AM
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I'll give it another go tomarrow, thanks gentlemen.
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Old 08-07-2003, 06:21 AM
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I'm proud to say that after a 2 weeks of battling (and learning to use a torch) i've concored the studs! Turns out that heating from the case cylinder bore is the way to go for those really hard studs. Now that i have free time for a couple of weeks, i should see about how i'm going to get my roll bar in the car since my mig welder is satan .
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Old 08-11-2003, 06:46 AM
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To reitterate an earlier post of mine I would have suggested to heat the stud, not the case.

Why?? well because of all the previously noted concerns about damaging the case.

Propane will not do the job, it will not get the stud hot enough.

Heat the stud until it just turns red, Per Bob W above. The reason you cannot do this to the case is that is will not turn color and suddenly melt on you. Once the stud has turned red you can be assured that the loctite bonds that have been holding the stud in place are GONE, broken. The stud, after cooling a bit, will back out easily.

The case sucks so much heat out that heating just the stud is a pretty safe method. The stud gets red, the case is much much cooler and will not be damaged. If you heat the case at the base, it will certainly work, but you run the risk of overdoing it and having a meltdown.

Last edited by snowman; 08-11-2003 at 08:38 PM..
Old 08-11-2003, 08:34 PM
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Well, with a small flame and 7psi regulated on both tanks, the flame isn't as hot as you'd think. Or at least it's hot, but the btu output i'd imagine isn't quite as high. With low pressure and a wide tip, the flame's low and it's not quite as concentrated as a smaller one, or at least that's my impression of it. Let me say as well that an assistant to keep constant pressure on the stud, while heating, till it breaks is basically a must because without it's pretty tough to balance the torch and pull/push on the wrench.
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Old 08-12-2003, 07:03 AM
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Snowman, this is not the first time I have seen you make this suggestion but it is dead wrong.

If you only heat the stud and not the case you are only going to make the stud expand in the bore and tighten.

One of the secrets of stud removal is cooling the stud when the hole is at its maximum temperature to break any bonding between the two and to give you maximum clearance which will also reduce damage to the threads.
Old 08-12-2003, 07:13 PM
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The stud is NOT held in by pressure from the case! It is held in by loctite, a glue. If you break the bond of the glue, the stud will not be held in, heat does this. A small ammount of heat will weaken the bond, but not break it, so much effort is still required, the right ammount of heat, DESTROYS the bond.

There is almost NO temperature difference between the stud and the case, no matter which one you heat up first. Heat will make the case expand a little more than the stud, due th the difference in coefficients of expansion, so something may be gained, but again due the the intimate contact between the case and stud there is NO practical temperature difference between them.

You may say it is dead wrong, but you are wrong in saying so. IT WORKS. IF you have tried this and the stud dosen't back out very easily, it is because you didn't get the stud hot enough to break the glues bond. Once this bond is broken the stud will almost fall out, ie not much more than finger tight, unless the threads have been buggered. I have done this repeatedly, I have seen this done repeatedly, I have been told that it works by a professor of automotive machine shop technology, who has been using this method and teaching it for over 30 years, I have seen this demonstrated a dozen times, without failure, I have done this myself untold times without failure, IT WORKS!

Last edited by snowman; 08-12-2003 at 07:38 PM..
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Bad theory there Snowman. What magical force do you think holds on fasteners that don't use locktite or similar chemicals?

Corrosion and metal bonding are the two of the most powerful forces that keep fasteners from coming apart like they should. All the heat in the world will not do much to change these problems unless you use the heat in a way that will break the bonded surfaces apart and provide additional clearance for the corroded surfaces to move by one another.

Quote:
I have done this repeatedly, I have seen this done repeatedly, I have been told that it works by a professor of automotive machine shop technology, who has been using this method and teaching it for over 30 years, I have seen this demonstrated a dozen times, without failure, I have done this myself untold times without failure, IT WORKS!
If you stood on your head and removed studs it does not mean that the two events are related to each other.

In addition to years spent working in an automotive machine shop and additional years spent working on cars and motorcycles I know what I am talking about here.

If that is not enough for you I also got a degree in aerospace engineering while turning wrenches so I can also back up a lot of real world experience with a thourough understanding of metalurgy and mechanics.

Before you are expected to design aircraft or automobiles they teach you quite a bit about fastener technolgy on your way to a BSAE. Fasteners make the world go around after all.

Last edited by 350HP930; 08-12-2003 at 08:11 PM..
Old 08-12-2003, 08:09 PM
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So what about the professor and his zillions of students( mostly mechanics who do real day to day work) who all tend to agree with him?

The heat does also a lot of good on metal corrosion, and breaking any bond it may have made. The reason it breaks this bond is the slight difference in coefficients of expansion of the metals.

Ask almost any mechanic. Add a bunch of heat from a torch and it will almost invaribly make the thing come apart, easily.

Last edited by snowman; 08-12-2003 at 09:11 PM..
Old 08-12-2003, 09:04 PM
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Have you bothered to concider that your professor may be mistaken? Just cause someone lands a job at the local community college does not mean that everything they believe is automatically correct.

Its unfortunate to think that this bogus information is being passed down to his students.

As both an engineer and a mechanic I have seen my fare share of bogus 'knowledge' being passed around since most people do not have the insight or training to seperate the wheat from the chaff.

As I already stated your method will only push surfaces together, not pull them apart. Its kind of hard to break a bond using compression instead of tension. While your theory about burning out locktite is correct and probably explains why you think your method works it will not do jack squat for corroded and bonded fasteners.

Thats the facts and you will probably refuse to believe me since I have seen this argument made in other threads to you before yet you still appear to believe your own experience instead of dozens of other people who know better.
Old 08-12-2003, 09:28 PM
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Loctite breaks down at a certain temperature, that is, it ceases to exhist. Thats why the loctite goes away, not any mechanical forces. The method does work. Ask anyone who has tried it. If you have not, do so. I have and it DOES work. As to corroded fasteners, it also does seem to work, I would hazard a guess that it is because of the difference in expansion rates. Once the "bond" is broken, things just come apart, relatively easily.

As to expansion rates, and trasfer of heat, I have personally analyzed this, and after careful consideration know to almost a certainty that the temperature differance between the stud and case is almost zero, after a period of only 3 seconds. There is almost NO difference between methods of heating, the case or stud. The Key difference is that the stud changes color, the case does not.
If you heat the stud until it just turns red, and then STOP, you will have a 2 or 3 second safty margin for the case. This may not sound like a lot but it is enouth. Letting them cool for 3 seconds or more guarentees they are at the same or nearly the same temp. At that point the case may acutally be slightly larger, due to the larger coefficient of expansion and the stud just a little smaller. Relatively speaking. In any case the epoxy is gone and if it will come apart, it will.

Last edited by snowman; 08-12-2003 at 09:47 PM..
Old 08-12-2003, 09:37 PM
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