I have a 96 Tioga with a 454 that has two busted studs on the exhaust manifold. I couldn't pass up a deal on this thing so I bought knowing it leaked a little but the leak has gotten worse so now the repair.One of the broken studs sticks out of the manifold hole a little so I should be able to get that one but the other stud broke at the threads inside the head. In fact, there's about two rows of threads left that will thread back and tighten a little. That's obviously how the PO handled it because there's 3 gaskets on this side.I'm not sure what to do at this point. I live in the Country and the closest dealer want's $1100 to do the job which would require me putting it back together and coughing up the money not to mention delaying our vacation time. How can I get the rest of that stud out or can I thread the busted piece back in and weld it into/onto the head?

After removing the manifold, a good welder can "blow" the stud out pretty easily and not damage the threads at all. I have a welder friend who works on heavy equipment and does this all the time.

I have repaired a few like this in previous yrs. The one that is sticking out will be simple if you have a welder. The one with no threads sticking out can be more difficult. At the least, you will need to remove the exhaust manifold, then find a nut that is slightly larger than the stud that's sticking out of the head. Place the nut over the stud and weld in the center of the nut, welding it to the stud. After it cools a little, simply back it out.Since you have one stud that is broke in the head, you will most likely need to remove the head. It will make it much easier for both studs to be removed. The other stud will have to be drilled out dead center of the stud with a bit about half the size/diameter of the stud. Then insert the appropriate size ease out into the drilled stud. lightly tap on it with a hammer and turn slowly to remove the stud. It's a very tedious job. It may be best to just remove the head and take to a local machine shop where they already have all the necessary tools to properly do the job if your uncomfortable with attempting this on your own. Wish I knew of an easier way, but that's about it to do it right.

My ancient Honda motorcycle had lots of problems with broken studs. I bought a stud extractor set from Sears. Basically, you drill a hole right up the center of the broken stud, then thread the extractor in. As it has elongated left-hand threads, it goes right in until tight. From that point, you just keep on turning, now unscrewing the broken stud.:)Lynn

If you do not fix it, you will proably burn or warp valvesfrom colder air leaking back in thru the leak area.

There are a few options ... buy an "easy-out" and try to get the stud out with that.The other option is to drill it out and install a Heli-Coil or Perma-Coil product.

Chevy 454 broken exhaust studs...What to do now?

20 Replies

indyzmike
Explorer
Jun 16, 2013
I agree that an "easy out" is the method to try. If the stud is broken off crooked, use a Dremel tool to flatten or cup the end. That way it will be easier to drill in the center.

If you drill too small of a hole, you would use too small of an easy-out and it might break off. This is bad as you cannot drill out an easy-out. They are too hard.

It is also bad to drill too big of a hole because you weaken the remaining wall of the stud. When you put the easy-out into the stud, the stud expands and will lock in the hole. This also happens if the hole is too close to one side of the stud.

Be patient and gentle, drills and easy-outs like to break.
flash_flood
Explorer
Jun 16, 2013
rode2nowhere wrote:
Heck while in there put a high lift cam and dual quad setup,,lol. Just kidding, if all that's wrong is a broken stud and/or manifold that's good.

lol, thanks man. I told my fiance I wanted to put a remote turbo on it. She thinks I'm crazy but I pointed out to her that it's the only vehicle we have that's not boosted one way or the other.
rode2nowhere
Explorer
Jun 16, 2013
Heck while in there put a high lift cam and dual quad setup,,lol. Just kidding, if all that's wrong is a broken stud and/or manifold that's good.
flash_flood
Explorer
Jun 16, 2013
I didn't expect so many replies so soon. With so many it makes it difficult to address everyone so I'd like to thank you all for responding first.

I didn't get a chance to work on it today. Another issue came up with the propane so I'll leave that for another topic. Being that it's fathers day tomorrow I'll probably hold off until Monday. I did get a chance to go to town today to get an easy out kit, new gasket, new stud kit, some anti seize, and some PB blaster. I forgot the doughnut gasket for the collector but with any luck, I can reuse the old.

My main concern is being able to actually drill in there. It looks like I may not be so lucky. I'm going to remove the front tire and inner fender well to see if I can get it or not. I really don't want to pull the head right now so if it comes down to it I may go without one stud and hope it lasts long enough for one trip. We are planning to hit the road soon.

As far as the stock header goes, I haven't fully inspected it so I do not know if it is cracked. I'll need to find a machine shop if it needs resurfacing. I was also looking at Summit for a replacement should I need to but I'm not sure which one it would be..

This one looks more like the original because of the heat shield.

Header 1

But there's also this one..

Header 2

But then I started thinking...If these stock manifolds suck anyway, would it be crazy to put a set of headers on it and maybe replace the stock cat and muffler. I wouldn't want it to be loud but the stock gear is huge and looks restrictive. I wonder if this thing would benefit from a free flowing exhaust and maybe even a little tuning? I guess mileage is gonna suck regardless so maybe I'm over thinking this too much as I tend to do with things.
KMLsquared
Explorer
Jun 15, 2013
Soak the heck out of it with PB Blaster or kroil oil for days before you attempt any extrication.
jdog
Explorer
Jun 15, 2013
A stainless bolt and nut will gall if you don't use anti-seize on the threads. You will have a big problem if stainless on stainless seizes. I am not sure about stainless on cast iron. Use anti-seize to be safe.
j-d
Explorer II
Jun 15, 2013
Reports of successful drilling suggest that we don't want to go back in with hardened or stainless fasteners. I haven't seen it myself, but have it on good authority that stainless becomes hard and brittle when subjected to high heat like exhaust. I replaced a set with stainless not knowing this and they never broke.
pauldub
Explorer
Jun 15, 2013
I have successfully drilled one out to the inside diameter of the bolt threads and then just patiently picked the remaining bolt threads out of the threads in the head.
usmohls2
Explorer
Jun 15, 2013
Don't forget to have the exhaust manifold re-surfaced before installation.
rode2nowhere
Explorer
Jun 15, 2013
Have also used " extractor " welding rods, doesn't burn into threads just the broken bolt, then weld a nut on the end of it and screw it out