Stud extractor

[TimShoubridge]

Evening all.........I just know that one (or many) of you have the answer to this one at the tips of your fingers, so I should be out in the shed later.

I've bought a second hand engine with 1 stud & 1 bolt sheared off 1 of the cylinder heads. I've so far used 2 tins of penetrating oil and things look ready to be attacked.

Now, the difficult part seems to be using the tony hart stud extractor. First screw on the "big bit", then screw on the "little bit" through the middle of the big bit. What now? Which one do I work on and which way?

As you can tell, my engineering skills are on a par with those of a 3 year old on this one, so any help will be much appreciated.

Tim

[Kevin Garrod]

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Tim

Just in case no-one comes straight back with the correct answer, my best guess would be turn the big bit anticlockwise.

I used a self-gripping stud extractor and as you know had no problems

[TimShoubridge]

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Kevin Garrod wrote:

Tim

Just in case no-one comes straight back with the correct answer, my best guess would be turn the big bit anticlockwise.

I used a self-gripping stud extractor and as you know had no problems

Hi Kevin,

I think I tried that and it just cam off the stud. :X

[stustag]

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Have you got a picture Tim or any instructions? If all else fails as Kevin said try the big bit anticlockwise.

Stuart

[Kevin Garrod]

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Perhaps you need to tighten the small bit more? I assume it works by locking the 2 bits together. The only other option would be to turn the small bit anti-clockwise, but that would just undo that bit.

Someone out there must have used one before:?

[stustag]

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Don't want to dishearten you but have a read of this!:shock:

http://forum.triumphdolomite.co.uk/v...347e40f35d5ba1

Is the stud flush with the block or some stud still showing?

I have a stud extractor that fits on the end of a 3/4 Rachet or breaker bar and has a hole in it then a knurled cam that comes round and grips the stud and hopefully undoes it!

If not then its drill and tap time if comes to this let me know and I'll sort the drill size out for you.

Stuart

[TimShoubridge]

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Thanks for replies so far......

1. I'll tighten it up and then try the big nut trick.

2. No instructions. Bought secondhand, so if anyone has instructions I'd love to see a copy.

3. 1 stud broken off level with head. 1 bolt broken off below level of head. Both should be ok but the drill out option is crossing my mind. Stuart, yes please...drill size appreciated. Any idea on helicoil size?

4. Could be purchasing another stud extractor.

Off to shed to give it a whack :shock:

Tim

[Mark S]

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Kevin Garrod wrote:

Perhaps you need to tighten the small bit more? I assume it works by locking the 2 bits together. The only other option would be to turn the small bit anti-clockwise, but that would just undo that bit.

Someone out there must have used one before:?

Clean the oil or grease off the stud and tool, keep tightening the two parts together and trying until eventually the tool no longer turns on the stud and the stud unscrews.This is not always easy to judge and many a time I thought the stud was unscrewing when the tool was screwing off the stud.

It's a good idea to use a socket and breaker bar or better still a torque wrench to undo as you can support both ends andprevent pulling at the side of the stud.

Tighten the tool too much and the stud will snap, apply too much torque trying to undo the stud and it will snap.You could tryclockwise, anti clockwise in an attempt to break the corrosion, but I found that this didn't work.

I got 7/10 this way out of an engine that had been stood for 5 years, therope trick bumped the heads up enough to saw the others off. The sawn off studswere a pig to push out of the heads though, even with a 15 tonne press!

If you have a bolt and stud snapped off in the same head you may be stuck. I've heard of people welding a nut to the flush stud to get it out,but can't say if this works since I haven't tried it.

Hope this helps,

Mark.

[TimShoubridge]

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Mark S wrote:

Kevin Garrod wrote:

Perhaps you need to tighten the small bit more? I assume it works by locking the 2 bits together. The only other option would be to turn the small bit anti-clockwise, but that would just undo that bit.

Someone out there must have used one before:?

Clean the oil or grease off the stud and tool, keep tightening the two parts together and trying until eventually the tool no longer turns on the stud and the stud unscrews.This is not always easy to judge and many a time I thought the stud was unscrewing when the tool was screwing off the stud.

It's a good idea to use a socket and breaker bar or better still a torque wrench to undo as you can support both ends andprevent pulling at the side of the stud.

Tighten the tool too much and the stud will snap, apply too much torque trying to undo the stud and it will snap.You could tryclockwise, anti clockwise in an attempt to break the corrosion, but I found that this didn't work.

I got 7/10 this way out of an engine that had been stood for 5 years, therope trick bumped the heads up enough to saw the others off. The sawn off studswere a pig to push out of the heads though, even with a 15 tonne press!

If you have a bolt and stud snapped off in the same head you may be stuck. I've heard of people welding a nut to the flush stud to get it out,but can't say if this works since I haven't tried it.

Hope this helps,

Mark.

Hi Mark,

Just to get this right, screw the big bit onto the stud until it wont go any further, then screw the llittle bit through the middle until it wont go any further? Then tighten which one? small or large nut?

On a positive note, 4 out of 5 bolts on other head just came off easily. Last one in soak now.

Tim

[Mark S]

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Tighten the two pieces together likelock nuts. I used two ring spanners to do this.

Mark

[stustag]

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Hi Tim

The stud is a 7/16 UNC 2B thread in the block and the recommended drill size would have been 9.4mm before tapping.

This drill size will drill to the minor diameter of the thread and therefore if your really careful you can re tap the hole out again to the original thread size.

Or you can wire insert tap the hole (Helicoil is a trade name) and you will need 11.508mm drill plus kit which can be found here.

http://www.emhart-vic.com/emhart2/sc...A1CA20BCDEE48F

Have fun!

Stuart

[alan_thomas]

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Tim, Can you clarify. My understanding is that you have one head still stuck on with 1 bolt and 1 stud sheared off level with the top of the head? Is this right?

If yes it seems premature to start talking of helicoils because when you do get the head off the remaining stud usually unscrews from the block quite easily. The problem is the stud is 'bonded' to the head by corrosion not that it is stuck in the block.

I have never had any success using the self gripping type of extractor after all if it was stuck enough to shear a high tensile 7/16ths stud why should anything that grips with friction move it? Also dont try the left hand thread 'E-Z-out' type where you drill a hole down the stud and then wind in the E-Z-out. They always break before shifting these big studs and then you have a broken piece of immensely hard material stopping you from drilling it out further. Likewise it is impossible to drill down the centre of the long stud without wandering off and into the head.

2 methods have always worked for me (I have a long, love/ hatehistory with TR7 and sprint heads!) First off heat / quench cycles. I also make a lake of pentrating oil (Iswear by'plusgas') by surrounding the broken stud with a ring of plasticine then filling it with the oil and leaving it for days.

Then to remove the head after the 'loosening treatment' I use the 'rope trick'. wind the engine around to the stroke where the cylinder that is immediately next to the broken stud is on the compression stoke, back off to move the piston half way down the feed some nylon rope thru the plug hole (several feet usually) leave the end hanging out. then with a long bar force the engine over the compression stroke. It is suprising how this can first break the gasket seal then push the head up very slightly on the broken stud.

More penetrating oil, more time then repeat. Hopefully you get a gap big enough to feed a hacksaw blade thru and then you can saw thru the studs. Word of warning if you don't want to mark the block or heads try to cut a couple of bits of 18swg steel sheet and slide them between the block and head and then saw between them.

They always come off in the end. Drifting thesawn off stud out of the head when its off is suprisingly easy and, like I say, getting the remaining stud out of the block offers little resistance.

Good luck - Alan

[Mpower738]

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In the early 90's I had a head stuck with the ends of some of the studs broken off from welding nuts on and turning them, incidentally this technique worked very well on the other head. I read in the club magazine of a firm somewhere that had a factory head extractor tool.

I remember driving a few hours from dorset, and the tool doing the trick in a matter of minutes, but I can't remember where it was exactly. The South East somewhere I think.

The tool was a large steel plate that in turn had shaped plates which bolted onto the exhaust manifold face and inlet manifold face. Large diameter bolts with inverted cone shaped ends screwed down onto the studs at the appropriate angleand jacked the head off far enough to cut the studs. I thnk it might have been a Saab tool but I'm not sure.

Does anyone else know of that tool and what became of it? If it still exists it would be handy if a club member were to come by it, or at least be able to borrow it for a while to make a copy.

Good luck getting the head off Tim, it's a pig of a job when they're really stuck.

Doug.

[TimShoubridge]

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Thanks to all for words of wisdom, advice.......and comfort .

Still smiling though......

[Bob Heritage]

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Hi Tim

I have to back Alan on this one. The cam type extractors usually break or ream metal off the stud so that it does not grip any longer. It is a must to keep the metal dry and free from oil/grease where the extractor fits or it will just slip. When you get the head off you can usually punch the stud through the head and if you have any stud showing in theblock a pair of mole grips will take it out. It is the corrosion in the head and not the block that is causing the trouble. I think you will have more trouble lifting the head with one stud and one bolt sheared as they are wedge shape. Try not to drill out unless absolutely necessary because you will more than likely damage the head, best left to a machine shop where they can drill parallel. Good luck.

Bob