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Broken manifold stud, Advice..FML

GIACUser

Master Wallet Mechanic
My question was more along the lines of welder setup. In theory, I know the goal is to weld a nut onto the stud. In practice though, exact welder setup makes a huge difference in whether the weld is strong enough to hold. Mig vs flux core, wire feed rates, amp settings, gas flow settings, wire type, etc are more the questions I have.
Here is a youtube with more welding info along with removal of stud broken deep or surface (weld bolt on)

 

GIACUser

Master Wallet Mechanic
My question was more along the lines of welder setup. In theory, I know the goal is to weld a nut onto the stud. In practice though, exact welder setup makes a huge difference in whether the weld is strong enough to hold. Mig vs flux core, wire feed rates, amp settings, gas flow settings, wire type, etc are more the questions I have.
He discusses that in the video and even shows you the settings on the panel of his Miller mig setup. In the comments they discuss the questions you bring up.
 

king1138

Ready to race!
My question was more along the lines of welder setup. In theory, I know the goal is to weld a nut onto the stud. In practice though, exact welder setup makes a huge difference in whether the weld is strong enough to hold. Mig vs flux core, wire feed rates, amp settings, gas flow settings, wire type, etc are more the questions I have.
Since every welder is different, and lots of things affect them like ambient temp and elevation, it doesn't do a lot of good to start with someone else's specs. I recommend setting up your MIG welder by welding some practice beads on steel and fiddling with the settings until you are satisfied with the specs. Then you should be good to go!
 

GIACUser

Master Wallet Mechanic
Since every welder is different, and lots of things affect them like ambient temp and elevation, it doesn't do a lot of good to start with someone else's specs. I recommend setting up your MIG welder by welding some practice beads on steel and fiddling with the settings until you are satisfied with the specs. Then you should be good to go!

Exactly, just fiddle with it a bit
 

JOHNDERS2586

Passed Driver's Ed
Just a follow-up. I appreciate all the info everyone provided here. Despite the fact that id like to "do it right" an fix the issue I took the low road and just bolted the new turbo up without it. Few reasons 1 if I attempted to fix I was afraid id mess it up even worse as I have 0 experience with welding and Heli coil and all of that.... 2 I just spent my allowance of cash on the parts themselves and couldn't spare who knows how much to take it somewhere to do it an then not to mention suffer listening to my wife b%tch about it.. So far an its been several thousand miles now, I have not had any ill effects. Car has been running great.. So lets hope the gasket holds indefinitely. I don't recommend going this route to anyone but I had to make a compromise, an so far I've been okay.
 

TroyBoy

Ready to race!
NICE! Sounds like you are okay and got the advice from the Pro's you needed

Also I have tried superglue. Glue the broken stud back together and then try to twist it out.
And to add...for anyone else in future. The right angled drill works great, I had to do this also on one of my cars, also there bit attachment (for any drill) works nicely

Once the stud is out Helicoil are very easy to use, I had no experience with them until I did with no issue. Twist it in and go once the hole is good.
 

zrickety

The Fixer
The driver side stud snapped on my car recently while reinstalling the turbo. It broke a few mm below the head surface and I was being lazy and didn’t feel like pulling the engine. I can confirm that it’s a pain but not impossible to drill out the broken stud. You’ll need a right angle drill, drill bits ranging from 1/8 to 21/64 in 1/64 increments, a mirror, and a shit ton patience. I did try to drill then extract the broken stud with both straight and spiral flute extractors, but it didn’t budge and I wasn’t going to risk breaking off an extractor. I ended up just drilling the stud out completely, then tapping for a M8x1.25 Helicoil.

View attachment 258280

There’s a decent amount of room once the cowl trim is removed
View attachment 258282

It’s important to center punch the broken stud to prevent the drill bit from walking. Doing this properly is a critical first step.
View attachment 258281

Next up is starting with a 1/8” drill bit and plenty of tapping oil. Use slow RPMs and take your time here. If you feel any resistance, reverse and clean the shavings from the bit. Also make sure the drill angle is correct, again a mirror here is key. Step up to the next 1/64 size bit and repeat until the stud is drilled completely out. The Helicoil will require drilling an oversized hole to the insert to thread into after tapping.

View attachment 258283


Here’s what the final result will be with Helicoil installed. At that point I installed a new stud proceeded with the turbo install.
View attachment 258284


Welding a nut onto the stud is another option. It involves using a flux core or mig welder to build up the stud and then placing a nut over the now protruding stud. I’m not sure this is possible with the engine still in the car, but it seems like a decent alternative to drilling. It’s also a good option if the passenger side stud breaks, because there’s very limited access to drill on that side due to the head design.
Love that Makita drill, nice post.
 
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