Exhaust Manifold Stud Broken Off

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Re: Exhaust Manifold Stud Broken Off

Post by Adam » Mon Sep 26, 2022 4:19 pm

Use a dremmel and grind the remains concave. drill with a small bit all the way through the stud, dont drill into the water jacket, slowly increase drill size till you hit block threads,, use a pick or tap or what not and cleanout the hole. Best if engienis on the ground on its side. If you hit the water jacket, just seal the new stud in place. No big deal

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Re: Exhaust Manifold Stud Broken Off

Post by Ron D » Mon Sep 26, 2022 4:48 pm

I had to do that once when there wasn't enough busted stud left to get a good weld on a nut.
Hair raising. Takes some precision to keep the bits centered. But it worked pretty good.
Very good feeling to pick out the last of the threads and run a thread chase into the hole.

On a different stud, the welded nut thing worked with equal good feeling.

And Donovan's post above always bears repeating: :shock:
Donovan wrote:
Thu Mar 24, 2022 9:36 am
Strongly, strongly suggest you let a professional get the stud out. A friend of mine has a machine shop and I can’t tell you how many times blocks were brought in that were screwed up by the owner or friend trying to get a broken stud or bolt out of a block. Very commonly the more the owner tried to get it out, the higher the cost to fix it!
Good luck,
Donovan.
Good luck!
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Re: Exhaust Manifold Stud Broken Off

Post by Scrumps » Tue Sep 27, 2022 12:51 am

Hi,

I’ve just sorted on for a friend.

I tried all the usual methods and ended up putting it on my milling machine, levelling the flange and dialling in the position of the stud and then milling out the old stud.

I managed to recover the thread and fitted a new stud for him.

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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Sun Aug 06, 2023 4:40 pm

Hi guys,

Well after 18 months and borrowing a $700.00 precision machine for help doing this, I still have yet to be able to drill out the stud in a manner that I feel comfortable with. I attempted to get it centered properly with that $700.00 tool but was not successful.

After 18 months I am at the point where I would rather just put everything back together again and deal with having a stud missing.

That being said, if any of you reached the same conclusion what would you do to make the best effort for no exhaust leak with this circumstance? Should I double-up the exhaust manifold gasket? Is there a particular exhaust manifold sealant that I should use versus another that would, if applied around the missing stud would prevent blow by?

I understand the best first choice is to replace the stud, but I have been working on this a year and a half and I do not want to go to the expense of pulling the engine. I worked my butt off on this machine for two and a half years to restore it. I am not in my forties any longer and just want to get everything back together again.

I would appreciate any and all advice from you guys that I have interacted with for years restoring it, but respect my decision to not have to pull the engine.

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Re: Exhaust Manifold Stud Broken Off

Post by W. Winget » Sun Aug 06, 2023 5:55 pm

And have you taken it to a machine shop to see if they can help?
Its just a stud, not a space ship, just saw an Asia machinist on You Tube made a hex head bolt by heating a rod and driving an allen wrench into the orange steel making the hex. My point is so much is possible with learned skill, a Machinist may have it done in an hour.
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Re: Exhaust Manifold Stud Broken Off

Post by dpcd67 » Sun Aug 06, 2023 8:33 pm

One word tip; Center drill. That is a type of drill used in machining. That is all I use for starting any hole, even in sheet metal, sometimes. Ok, more than one word. And I've drilled out broken off studs.
Just out of curiosity, what kind of machine for $700 did you buy?
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Re: Exhaust Manifold Stud Broken Off

Post by Adam » Mon Aug 07, 2023 6:09 am

18 months,, you could of pulled the engine in a day, It is in a tough spot, gonna need a small 90 degree drill with a 1 inch bit, just pull the engine and take it to the shop,, they will have it done in an hour.



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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 6:35 am

dpcd67 wrote:
Sun Aug 06, 2023 8:33 pm
One word tip; Center drill. That is a type of drill used in machining. That is all I use for starting any hole, even in sheet metal, sometimes. Ok, more than one word. And I've drilled out broken off studs.
Just out of curiosity, what kind of machine for $700 did you buy?
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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 6:36 am

W. Winget wrote:
Sun Aug 06, 2023 5:55 pm
And have you taken it to a machine shop to see if they can help?
Its just a stud, not a space ship, just saw an Asia machinist on You Tube made a hex head bolt by heating a rod and driving an allen wrench into the orange steel making the hex. My point is so much is possible with learned skill, a Machinist may have it done in an hour.
V/R W. Winget
That sure would be awesome if they can do that. I will post some latest photos and please let me know your opinion if there is enough meat on the stud to do that.

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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 7:02 am

thidisbogus wrote:
Mon Aug 07, 2023 6:36 am
W. Winget wrote:
Sun Aug 06, 2023 5:55 pm
And have you taken it to a machine shop to see if they can help?
Its just a stud, not a space ship, just saw an Asia machinist on You Tube made a hex head bolt by heating a rod and driving an allen wrench into the orange steel making the hex. My point is so much is possible with learned skill, a Machinist may have it done in an hour.
V/R W. Winget
That sure would be awesome if they can do that. I will post some latest photos and please let me know your opinion if there is enough meat on the stud to do that.
Image

Image

Image

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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 7:03 am

Image

Image

Image

Image

Image

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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 7:04 am

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Re: Exhaust Manifold Stud Broken Off

Post by W. Winget » Mon Aug 07, 2023 7:22 am

Had to work the link for the photos then you fixed it. Anyway I see two possibilities, and the correct solution is drill and helicoil the hole (let a machinist or mechanic do it right)
2nd possibility for redneck repair would be to just weld a stud on, grind away the base to almost no weld then put on manifold...the REDNECK way...
possibly drilling the inner manifold hole a little for weld clearance. (NOT the preferred /recommended technique.)

Why it needs the machinist/mechanic to do a helicoil insert is here:
crack.jpg
CRACK
This compromises the hole even if you removed the stud remnant. (Ironically it also lets penetrant into the deeper threads)

You could print the photos and take them around locally to see if anyone will tackle it. Price should be under $200 I would figure.

Now 3rd alternative is if you had a MIG welder, it may have enough to grab onto if you placed a nut over the remnant and set power on high, zapping the MIG wire into the hole onto the stud, filling up the nut. Then after it turns back to metal color following cooling, try unscrewing it, repeating possibly three times if needed.

Heck this one could be as simple as heating cherry, cooling with can of air (computer keyboard cleaner) a few times (red/cool/red/cool) ahrinking the stud metal then using a left hand drill to twist it out.
Still should helicoil it for that crack "run" to cease.
V/R W. Winget
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Re: Exhaust Manifold Stud Broken Off

Post by thidisbogus » Mon Aug 07, 2023 9:04 am

W. Winget wrote:
Mon Aug 07, 2023 7:22 am
Had to work the link for the photos then you fixed it. Anyway I see two possibilities, and the correct solution is drill and helicoil the hole (let a machinist or mechanic do it right)
2nd possibility for redneck repair would be to just weld a stud on, grind away the base to almost no weld then put on manifold...the REDNECK way...
possibly drilling the inner manifold hole a little for weld clearance. (NOT the preferred /recommended technique.)

Why it needs the machinist/mechanic to do a helicoil insert is here:
crack.jpg
This compromises the hole even if you removed the stud remnant. (Ironically it also lets penetrant into the deeper threads)

You could print the photos and take them around locally to see if anyone will tackle it. Price should be under $200 I would figure.

Now 3rd alternative is if you had a MIG welder, it may have enough to grab onto if you placed a nut over the remnant and set power on high, zapping the MIG wire into the hole onto the stud, filling up the nut. Then after it turns back to metal color following cooling, try unscrewing it, repeating possibly three times if needed.

Heck this one could be as simple as heating cherry, cooling with can of air (computer keyboard cleaner) a few times (red/cool/red/cool) ahrinking the stud metal then using a left hand drill to twist it out.
Still should helicoil it for that crack "run" to cease.
V/R W. Winget
Thank you so much all of you for your detailed reply. I am alarmed a little seeing that crack you pointed out. Is that a normal thing? Is that going to cause a leak with anything? I will definitely reach out to machinists and welders and see what I can find.

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Re: Exhaust Manifold Stud Broken Off

Post by W. Winget » Mon Aug 07, 2023 9:17 am

Block is 80 years old, it will have some stress cracks somewhere from heat/cool cycle.
A machinist can ensure it (crack) doesn't run further and possibly enter the cooling jacket area, other than that the thread insert will ensure the manifold is able to be tightened in place properly for the years to come.
Flash a couple of prints to some local places (machine shops and OLD Mechanics) then tow it over to the one that seems to give the best feel for capability is my recommendation.
V/R W. Winget
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