We just acquired a VW diesel rabbit for $400. The intake manifold fell off after all four of its mounting bolts broke.
One of these broke off sufficiently above the machined side of the head that we were able to turn it out by striking the burr with a chisel.
However, the other three are broken slightly beneath the surface.
Ideally, we'd like to remove these without having to remove the Indian .. er.. engine...
I am wondering about the possibility of striking an arc on the end of each bolt and building this up until it's above the surface and then turning 'em out with a chisel as we did the first one.
Some time ago I read about a trick like this where the guy strick the arc inside a small piece of copper tubing placed into the hole. However, I presume that in his case he was working with a steel bolt inside a steel head and that the purpose of the copper tubing was to keep from welding the stud to the head.
So the plan is to use some reasonably small rod at a suitably low amperage WITHOUT the copper tubing. As I perceive things the aluminum will not melt because it is a better conductor of heat than the steel.
However, in my mind everything is easy. It's at the "reality interface" that things start to go wrong.
So, is this a viable plan? And if so, what rod flavor and diameter would YOU recommend.
All answers appreciated. Correct answers REALLY appreciated. Plan "b" is to remove the engine and drill 'em out.
There is just enough room between the work area and the firewall to make this doable if I bend the rod into an "L" shape.
Hold a nut centered over the broken stud . Strike an arc with that suitably small rod and weld the nut to the stud . Apply wrench to nut while still quite warm , stud should come right out . Worked well on a cyl head from a GM V6 with a couple of busted studs , but we had a bit more room than you do (heads were off) , and a mig welder .
A few refinements. Use a cellulosic rod, like 6011 or 6010 or the hole will fill with flux. I prefer to use a MIG or TIG when doing this so there is no flux to get in the way. Make sure to use a UNPLATED washer or nut or the zinc will explode in your arc and make the weld brittle. I always have a stock of bare steel square nuts around for welding threads to the backs of barstock.
Once you have it welded to the stud, and it is still hot, inject some penetrating lube into the bolt hole.(ie Liquid Wrench, Knockrloose, C-36) WD40 is not my choice for this, but if that is all you have... Some people use parrafin wax or peppermint oil, as they both have excellent wicking ability. Lock a pair of vise-grips to the nuts and start wiggling the nut back and forth, working the lube down into the threads. The threads should start to loosen up as you wiggle. Eventually it should break free enough to spin it out.
Once you have the stud out, chase the threads out with a tap.
Thanks for piping in!
I think we're gonna remove the engine just to give us a better chance of getting it right. At my age and level of ability, it's hard to imagine doing it just right, in a cramped and awkward position, with poor visiblity, three times in a row.
It's a whole lot easier to pull the head, but i have done the job in place many times with an air angle drill. I have had great results with reverse drills, these work great but the easy-out part is weak so i don't use it. http://www.aldn.com/drillout/drilloutparts.shtml Replace all the exhaust studs, the good ones will fail soon.
The difference between theory and practice is generally greater in practice than in theory.
CAUTION, I think this is FALSE, very false, if the arc contacts the aluminum I think you will find it melts easily and may make your problem worse.
I like 3/32 (or maybe 5/64) - 6010, YMMV
Note comments below regarding welding by sound.
This is a question that comes up frequently.
The standard answer is to weld a nut on the end of the broken stud or bolt. This is not always an easy job as it is difficult to align the nut to the broken stud and to make a good weld inside. The more experienced answer is to first weld on a washer with a hole slightly smaller than the broken bolt. I always keep a selection of thicker washers of various sizes on my rig for this purpose. Let the weld cool and clean the flux, THEN weld a nut to the washer, the nut can now be a lot larger and is easier to weld inside (or outside) and there is less danger of welding to the part you are trying to save. The shrinkage resulting from the cooling of the welds will help to loosen the stud, always allow to cool completely before torquing on it . This technique works well when the stud is not broken too far below the surface. It may require more than one attempt.
The following is from an earlier thread, subject 'here's a tough one, trying to remove a countersunk bolt'
also from the earlier thread, subject 'here's a tough one, trying to remove a countersunk bolt'
Note that this is a steel NOT copper pipe.
When this works properly it is great, but use CAUTION, a failure can make the problem a LOT worse, (don't ask, but I do own one very expensive carbide drill bit!).
Good luck, YMMV
Thanks for elaborating and expanding on the concept. I really like the "pipe trick". But here I'm dealing with the metric equivalent of probably a 1/4" diameter hole. Nevertheless, the washer and/or inverted cone concept definitely resonates.
A reverse rotation drill bit works well in most cases but I have used a piece of 1/8" X 1" X 2" long strap bent in an L shape with an appropriate size hole drilled in one end instead of a nut to weld to the stud. It is fairly easy to align with the broken stud and the L shape allows you to use a vicegrip or crescent wrench to turn out the stud after welding. I always use a slight rocking motion with application of penetrating oil to break the stud loose before attempting turning it out. Good luck Steve
On Sun, 13 May 2007 10:16:44 -0700, Vernon wrote:
Centre punch and left-handed drill bits. Heat also works quite well. Or penetrating oil left overnight.
Do all three ;)
EZ out's are misnamed. The number of times they acutally work versus snapping off is a not good ratio. Then you are stuck with a very hard EZ out in the center of the bolt, not good. Using an increasing series of left handed drills will usually grab the bolt and spin it out.
Jimmie D wrote:
"RoyJ" wrote: EZ out's are misnamed. The number of times they acutally work versus snapping off is a not good ratio. (clip) ^^^^^^^^^^^^^^^^^^^^^ The OP states that one of the studs was removed by rotating the projecting stub with a chisel. The others broke off below the surface. This suggests that they may not actually be frozen, but just hard to reach, so an EZ out would stand a good chance. The best screw extractors I have ever used are made by Snap-on, and consist of matched sets of drill, spline and nut. You drill a hole, drive in the hardened splined shaft, and then slip on the nut.
I have used a set of those for over 50 years. There are some other straight and spline removers that also look pretty good. The common tapered removers seem okay if the stud is sheared, but left hand drills usually take care of that. There has been so much discussion on this topic that someone should write a book! All of the techniques will work sometimes and sometimes none of them will. My policy is to go for drilling and tapping before I make the task harder.
I agree completely but want to add one thing- make sure you drill all the way through the broken bolts and studs so you can drive any broken removers through. I do not like removing bits of hardened steel from a deep hole. Brian
Never thought about driving them through. Usually don't have the option though. They are typically exhaust bolts that have crystallized, drilling as far as I get is all I'm up for.
Don Young wrote:
I have found that the welded bolt method works the best if you can't get at the stud. The other method I use is to drill the stud and then us a left handed tap on it. Then insert a left handed stud or bolt and turn it out. If the bolt snaps off you can still step drill the bolt up to near the minor diameter of the thread and just pick it out with a sharp pick.
The main thing is not to stick an easyout in it and snap it off. It isn't easy after that unless you have a tap burner or edm machine.