Broken exhaust stud removal

[JHZR2]

Put them snug (slightly more than finger tight) by using 2 nuts tightened against each other once the stud bottoms out. As long as you have enough threads to tighten the manifold the extra 4mm is not going to make any difference.

Can the two nut approach be used to remove studs too?

I want to get my turbo flange resurfaced, and wanted to try to remove the one stud that is still in the head. I tried to jam two nuts together, and loosen the stud.

No matter what I did, I couldn’t get any to budge. I was concerned to break studs so I didn’t go that hard on them, but the pair either just slips and loosens together, or if I hold the jam nut in place firmly, the other nut I’m turning left just slips against the other one and Infesr that I’ll either damage the stud threads (which are surely harder than the nut), or snap the stud.

Is there a better way? These have been soaking with Gibbs for days.

 

[Astro14]

A stud tool will grab the body of the stud and give you more grip without damaging the threads - of greater concern is snapping the stud from too much torque. Heating it red hot (oxy-acetylene) will help loosen it and it might be worth having the machine shop remove the studs at additional cost - they will have the tools and experience.

Start with a stud tool like this:

Lisle 71200 Stud Remover https://a.co/d/gNnuZcV

If it were me, I would be trying out my new inductive heater, and then my old stud tool.

 

[JHZR2]

A stud tool will grab the body of the stud and give you more grip without damaging the threads - of greater concern is snapping the stud from too much torque. Heating it red hot (oxy-acetylene) will help loosen it and it might be worth having the machine shop remove the studs at additional cost - they will have the tools and experience.

Start with a stud tool like this:

Lisle 71200 Stud Remover https://a.co/d/gNnuZcV

If it were me, I would be trying out my new inductive heater, and then my old stud tool.

Funny you said that. I just ordered an inductive heater!

The studs on the manifold, other than the fact that the hardware came apart perfectly after all this time, I’m not too concerned about damaging them or being in a pickle. I saw that lisle type but I was thinking to buy the Hazet one.

It’s the one remnant stud on my head that bugs me. I’d like to use all new, and I’m very fearful that I’ll break it off.

I’m also not sure I want to heat the steel stud versus the aluminum head. But the head is sick a thermal mass…

 

[Astro14]

I think the heat on the stud, which expands it into the surrounding manifold, also breaks it loose a bit from the corrosion in that manifold. Maybe a bit of heat, then shock cool it with something like this?

https://www.crcindustries.com/freeze-off-super-rust-penetrant-bolt-spray/

 

[JHZR2]

I think the heat on the stud, which expands it into the surrounding manifold, also breaks it loose a bit from the corrosion in that manifold. Maybe a bit of heat, then shock cool it with something like this?

https://www.crcindustries.com/freeze-off-super-rust-penetrant-bolt-spray/

For the studs in the manifold, I agree.

My only real concern is the CTE of steel versus aluminum for the stuck stud in the head, and what could happen if one expands much faster than the other. Obviously the steel is dumping large amount of heat through the interface into the aluminum, but the aluminum is sinking it away really really fast because it is such a big mass.

I’m not confident that I could actually heat the aluminum enough to make it matter.

Of course, the induction heater makes a ton of sense, because it’s so localized and close that it would make things really easy. Just double nut the stud, heat the stud at the base, then quench the stud while leaving the aluminum hot and try to twist out.

But if I really need to get the aluminum expanded versus the stud, that’s a bigger challenge. And if heating the stud and making it grow faster than the aluminum could damage the threads then I feel like I might be better off just reusing the OE stud….

The beautiful stainless ones that are on my manifold are a different story, because if worse comes to worse, they certainly can be drilled, tapped, machined, etc.

 

[DWS507]

You did an exceptional job,scary I'm sure,it was also a great watch and learning experience for those on this post

 

[Number_35]

Funny you said that. I just ordered an inductive heater!

The studs on the manifold, other than the fact that the hardware came apart perfectly after all this time, I’m not too concerned about damaging them or being in a pickle. I saw that lisle type but I was thinking to buy the Hazet one.

It’s the one remnant stud on my head that bugs me. I’d like to use all new, and I’m very fearful that I’ll break it off.

I’m also not sure I want to heat the steel stud versus the aluminum head. But the head is sick a thermal mass…

Which inductive heater did you order? I'm seriously considering ordering one as well.

 

[Trav]

M10x1.0?

Yes, a regular tap wouldn't fit in the space anyway. This was in a distribution block on the under body with the lines coming in from above then making an immediate 90 degree going off to the side and up to a rear wheel.

 

[Astro14]

Which inductive heater did you order? I'm seriously considering ordering one as well.

I have this one -

Induction Innovations - The Original Mini-Ductor II (MD-700) - Handheld Induction Heater with 3 Basic Coils, Rugged Carrier Case & Operations Manual to Safely Remove Nuts, Bolts, Bearings, & More https://a.co/d/03VCACLK

It’s amazing how quickly it heats up steel parts. Recently removed the remnants of some exhaust system bolts that broke after extensive corrosion. The stubs were locked into the aluminum subframe by the corrosion. All of this located right below the fuel tank. 10 seconds of inductive heat and the bolt stub was smoking. Came right out. Everything nearby was still cool.

 

[JHZR2]

A stud tool will grab the body of the stud and give you more grip without damaging the threads - of greater concern is snapping the stud from too much torque. Heating it red hot (oxy-acetylene) will help loosen it and it might be worth having the machine shop remove the studs at additional cost - they will have the tools and experience.

Start with a stud tool like this:

Lisle 71200 Stud Remover https://a.co/d/gNnuZcV

If it were me, I would be trying out my new inductive heater, and then my old stud tool.

Good news and bad news…


Good news - I got the one stuck stud on the block.

The lisle style would not work, but the Hazet style did.

The Hazet unit has three gripping surfaces that self-tighten.

Now the bad news. I think I ruined a stud on my exhaust manifold, and can’t get any out. Used inductive heating, used the different grip tools. Lots of torque. No dice. Three of the threads are probably ok, the other is this:

I think I need to have another thread on repair of this. If I can. I may be stuck.

I wanted to remove them so I could smooth this:

No dice. Induction works but I guess can’t get the stud hot enough. It can do a nut because there’s a heat transfer barrier. But the stud is so hard connected to the manifold that it just soaks up the heat.

Just putting induction on the stud never got hot enough.

 

[PandaBear]

Good news and bad news…


Good news - I got the one stuck stud on the block.

The lisle style would not work, but the Hazet style did.

View attachment 334515View attachment 334516

The Hazet unit has three gripping surfaces that self-tighten.

View attachment 334517

Now the bad news. I think I ruined a stud on my exhaust manifold, and can’t get any out. Used inductive heating, used the different grip tools. Lots of torque. No dice. Three of the threads are probably ok, the other is this:

View attachment 334518

I think I need to have another thread on repair of this. If I can. I may be stuck.

I wanted to remove them so I could smooth this:

View attachment 334520

No dice. Induction works but I guess can’t get the stud hot enough. It can do a nut because there’s a heat transfer barrier. But the stud is so hard connected to the manifold that it just soaks up the heat.

View attachment 334521

Just putting induction on the stud never got hot enough.

View attachment 334522

I am not sure if I understand correctly. Induction is a method to heat something using the coil and what you heat here is the bolt? The bolt is going to expand inside the manifold so it won't come out using heat, because you probably should heat the manifold and cool the stud instead.

Last time I have a distributor rotor bolt stuck inside a distributor shaft, I use a soldering iron to heat up the shaft's collar the bolt is in. I got that out eventually. Maybe you should try to gently heat the manifold evenly, then try to twist the bolt off after it is out of the oven / heater with a cool tool.

 

[JHZR2]

I am not sure if I understand correctly. Induction is a method to heat something using the coil and what you heat here is the bolt? The bolt is going to expand inside the manifold so it won't come out using heat, because you probably should heat the manifold and cool the stud instead.

Last time I have a distributor rotor bolt stuck inside a distributor shaft, I use a soldering iron to heat up the shaft's collar the bolt is in. I got that out eventually. Maybe you should try to gently heat the manifold evenly, then try to twist the bolt off after it is out of the oven / heater with a cool tool.

You’re absolutely right. As I noted elsewhere, that was indeed a concern of mine, but the hope was that I’d transfer enough heat into the manifold to help.

I had tried quenching just the stud with various methods but that wasnt enough. I think the holistic heating of the cast iron with the studs being cooled is key. Or drilling, etc.

 

[Pablo]

Heat then wax or

You’re absolutely right. As I noted elsewhere, that was indeed a concern of mine, but the hope was that I’d transfer enough heat into the manifold to help.

I had tried quenching just the stud with various methods but that wasnt enough. I think the holistic heating of the cast iron with the studs being cooled is key. Or drilling, etc.

Did you try heat then wax?

Heat then penetrant?

Heat then ice?

 

[JHZR2]

Heat then wax or

Did you try heat then wax?

Heat then penetrant?

Heat then ice?

Heat then penetrant, and heat then cool the stud.

 

[Pablo]

Heat then penetrant, and heat then cool the stud.

Ping ping ping lightly on the end of stud

Heat then get paraffin wax sucked into the threads when it cool

Trying to break the oxidation bond

 

[JHZR2]

Ping ping ping lightly on the end of stud

Heat then get paraffin wax sucked into the threads when it cool

Trying to break the oxidation bond

Yeah I should have mentioned I tried hitting it a bunch.

Since the stud is not saveable I might go air hammer.

But I think the key regardless is to try to get more heat on the manifold itself.

 

[Pablo]

Yeah I should have mentioned I tried hitting it a bunch.

Since the stud is not saveable I might go air hammer.

But I think the key regardless is to try to get more heat on the manifold itself.

Have you got the stud cherry red or hotter ?
I can’t post videos but look for that wax method you tube

 

[JHZR2]

Have you got the stud cherry red or hotter ?
I can’t post videos but look for that wax method you tube

That’s the thing, the stud won’t get cherry red. I think it has too good of contact and thus heat transfer with the manifold.

Two nuts on the threads will get cherry red. I guess they don’t have as good an interface to the thread to transfer heat.

Even then you can get one to glow and not the other. It’s pretty localized.

With the right wrap both will heat.

The stuff will get hot but not glow red even if the coils are.

And as others have said, an expanded stud could make it tighter if the cast iron doesn’t expand properly. I had hoped to get expansion of both then quench the stud but no luck.

 

[PandaBear]

Thinking outside the box here. Can you chase the thread down to a smaller size (i.e. #12 at 9.53mm instead of 10mm) and just use a smaller bolt (again #12 at 9.53mm instead of 10mm) to grab that specific one (i.e. a bolt that is less than 1mm smaller like going between metric and English unit), and leave the old stud in place?

Or, find a used manifold in the junkyard or eBay and just replace it? I know you want to save what you have and know the history of but sometimes you have to pick your battle and find an alternative.

 

[Pablo]

That’s the thing, the stud won’t get cherry red. I think it has too good of contact and thus heat transfer with the manifold.

Two nuts on the threads will get cherry red. I guess they don’t have as good an interface to the thread to transfer heat.

View attachment 335344

Even then you can get one to glow and not the other. It’s pretty localized.

View attachment 335345

With the right wrap both will heat.

View attachment 335346
The stuff will get hot but not glow red even if the coils are.

View attachment 335347

And as others have said, an expanded stud could make it tighter if the cast iron doesn’t expand properly. I had hoped to get expansion of both then quench the stud but no luck.

Do that then just use an old candle. When still hot - not that hot sans nuts - touch an old candle on the threads. Get the wax to suck in. May need to repeat. Then try to remove with two nuts