Exhaust stud stripped - removal ideas

[mrbenn]

So, with boring predictability, having removed the engine and gearbox virtually without issue (always helps if you disconnect everything) I have an issue with a stripped exhaust manifold stud in the head.

Interestingly, this one appears to be a shiny silver one rather than brass like the others (which are all fine, by the way).

Anyone got any brilliant ideas for removal?

I've tried:

- heating the area around the stud
- swearing at it
- cooling the stud
- heating the area around the stud, then cooling stud
- more swearing
- decent vice grips
- yet more swearing and a bit of crying
- using two nuts, turning the inner nut to back it out, just stripped more
- threats of the breakers yard
- stud extractor, got another on the borrow from a neighbour to try but not hopeful.

Any further ideas before I lose my mind?! Stud has not (yet) snapped.

As always, many thanks!

[philthehill]

If you cannot get the stud out by normal means as described above cut the stud off level with the head and carefully drill out the centre of the old stud with a 6.9mm drill (tapping size for 5/16" UNF) and re-tap the hole. If you are lucky - having used the 6.9mm drill you may be able to wind out the remains of the 5/16" UNF stud from the female threads in the head.
Best of luck.

[panky]

My procedure is a bit more crude than Phil's
The same thing happened to me on my camper engine, so out came the mig welder. I applied blobs of weld and built it up until there was enough to knock on an old socket(mole grips will do), a combination of all that heat and a decent grip on the stud made it come out easily

[simmitc]

Don't forget the obvious - soak it in penetrating oil / releasing fluid such as Plus Gas. Keep it soaked and let it work for a day, then try again.

[amgrave]

One idea that has got me out of trouble before is to heat the stud until glowing dull red avoiding the block. The idea is that by heating the stud only it will try to expand but the surrounding metal wont let it so it squeezes the stud a very small amount making it smaller. Let it cool down again and it should come out.

[anthony2]

I removed a stud by tapping the stud lightly and rapidly ,with a small hammer, whilst my assistant tried to undo the stud with a ring spanner,You get the same effect with garage air tools,

[bmcecosse]

The studs have never been brass.....the nuts are brass! But the studs are steel...

[mrbenn]

Thanks very much for all the advice and ideas, and correction on the stud material. The stud is currently soaking in it's latest bath of Plus Gas ready for another attempt at removal. I'll try heating the stud and letting it cool too - good tip.

I've got hold of another stud extractor, this one actually:

https://www.machinemart.co.uk/shop/prod ... -extractor

It screws on to the stud really tight so, in conjunction with the ideas here, I'm really hopeful something good will happen.

In case defeat is snatched from the jaws of victory, I've got some suitable drill bits to call upon.

A welder is something I don't have unfortunately. However, I'm this > < close to buying one just for this job alone!

It's good to know I'm not alone, even when I'm sat on the garage floor with my head in my hands!

Update soon.....

[MarkyB]

I'd never seen a stud extractor like that before I use this type with mostly success;
http://www.ebay.co.uk/itm/Sealey-Stud-R ... 20f5888a7d

[philthehill]

I have the earlier Sykes Pickavant version of the Sealey stud remover and this type of stud remover is excellent as the harder you pull the tighter the stud is gripped.
It has never failed me yet unless of course you pull to hard and end up with a broken stud and then out with the drill.

[bmcecosse]

A stillson wrench works fine - but the reality is that stud is quite likely to shear away....

[mrbenn]

Well, things have taken a turn alright.

I've made a good effort so far using decent quality tools (including a stud extractor as shown above - couldn't seem to get a grip on the stud with it for some reason, just kept slipping round, perhaps operator error!) and not budged the thing at all.

This afternoon I had another go. I started by tapping it all round with a hammer, then heated the stud before letting it cool. Then I broke out this:



Idea is that it grips the stud as tightly as possible before starting to loosen. It kept getting tighter and tighter. And tighter until I was really putting some force into it and then.... the stud just came undone I was certain it was going to snap, I think I was probably very lucky.

I'd wager it was a combination of things that got it out in the end, suffice to say I'm very relieved. Many thanks indeed for all for the ideas folks, much appreciated!

[M25VAN]

Well done.
Also you now have experience for the next time.

[bmcecosse]

Well done ! Throw it far far away..... And be sure to use BRASS nuts on the studs....

[mrbenn]

Thanks chaps. I've got replacement brass nuts ready to go on.

Fingers crossed it'll all go back together ok and be back out on the roads soon