exhaust/ intake manifold stud sheared

I had one snap off when I was rebuilding my truck. I drilled it out and replaced it with a bolt. No biggie. The outer 2 are through bolts, the inner two? I used a 3/8-16 1-3/4" bolt to replace the broken stud in my manifold.

Thanks again for all the input. I am in no hurry here, I have the correct sized hole for my ez-out drilled into the broken stud, I am going to proceed in getting what I need to complete the welding portion of this task, in the mean while I will heat the broken stud and the remaining stud with a propain torch as hot as I can get it, let it cool down and soak it in penetrating oil, daily, for a week or so, and report back......

T

Terrell---------I don't have any more techniques to suggest, but........everyone has their own idea of what the very best penetrating oil is, which is fine, but I've read a number of suggestions on this forum by others that a 50/50 mixture of acetone & transmission oil cannot be beat, hands down.......just my TCW.....

https://www.bing.com/videos/search?q=removing+broken+stud+bolt&view=detail&mid=551FE92604318DD5D6BE551FE92604318DD5D6BE&FORM=VIRE

Terrell---------I don't have any more techniques to suggest, but........everyone has their own idea of what the very best penetrating oil is, which is fine, but I've read a number of suggestions on this forum by others that a 50/50 mixture of acetone & transmission oil cannot be beat, hands down.......just my TCW.....

Acetone and ATF will separate and not stay mixed. If these two fluids are in conflict I have to question the ability of the two working together. I Googled this 50/50 mixture of ATF and acetone and the first and many following hits suggested the two products will not stay mixed. If you are using this mix, you should be aware that acetone will most likely react with the plastic and make a hole.

To keep the penetrating oil on the stud you can light a candle and drip wax in a circle around the stud making a little raised area to hold the fluid where you need it. Easy to clean off afterwards

Hello everyone, if you flip the exhaust manifold upside down and block the heat diverter open, there are two bosses cast into the manifold underneath the studs on the inside of the manifold. The studs do not go deep enough into the bosses to be flush on the inside of the manifold, so they make a perfect place to make a puddle of penetrating oil. When I first started doing this the puddle stayed for almost a day, now it soaks thru in about 30 minutes....I will keep soaking it until this weekend and see what happens.

Thanks, Terrell

Terell
Here is a crosscut view of a bolt in a threaded hole. There is some clearance between the two. If you have fluid flowing through you could use a punch and tap on the stud some from the boss side and then from the other side. Not too hard. Careful to not damage eny exposed threads may help loosen it up prior to using your easy out. As in the video down loaded in the previous post wiggling back and forth if it gets tight in the counter clockwise direction once it starts moving.

thread.gif (9.09 KiB) Viewed 2382 times

Success! Finally got the broken stud out of the manifold, turns out it is more like a lag bolt threads in the manifold itself, a bit smaller in diameter that the 3/8 portion of the stud. Looks like drilling out and tapping for a 3/8" bolt will be the way to go from here. I also welded the crack without a problem. Thanks for all of the help!

Terrell
Columbia, Mo.

http://lincolnmachine.com/tap_drill_chart.html
I wonder if someone put a helicoil in there.
This chart gives good information..