Broken exhaust stud removal

[JHZR2]

And while I’m at it…

Yes or no:

- reuse old studs that came out easily (if I can get nuts off and threads chased)?
- anti seize on the head side stud threads (black oxide steel studs into aluminum head)
- anti seize on exposed side (black oxide steel studs with copper nuts)
- nickel anti seize or something else?

 

[Nessism1]

That looks good.

Yes, on the LH drill bits. Harbor Freight sells a decent set for cheap.

Once you get a hole in the center of the old screw, you shouldn't need any more drill guides. Just check often to make sure you are drilling straight. Typically, the shell of the old screw will spin out as the wall size gets thin. Hope so anyway...

Regarding replacing the old studs, my vote is YES! Can't think of any reason NOT to use anti seize.

 

[AdmiralYoda]

This is a good start. I would use this bushing and ONLY this bushing as you step up in diameter. You'll never drill the next one you make in the same spot so it will be offset to the hole in the broken stud when you screw it in.

Leave this bushing in there and increase the size as much as you can so that the hole through the broken stud is centered. Use a standard bit so you don't back out the bushing.

At this point you should have a good enough pilot hole in the stud where you can increase the drill size and keep it straight. Use a screw extractor to try and back out the broken stud.

If the extractor doesn't work keep increasing the drill size through the pilot hole you made using LH drill bits. Eventually there won't much left and it will spin out.

 

[Trav]

I would use the bit you have and work my way up til there are only remnants of the threads left that you can grab with an easy out, left hand bits work well but on this with steel corroded in aluminum there is not much chance it will spin out.
Use new studs with copper nuts and use nickel anti seize.

 

[JHZR2]

I would use the bit you have and work my way up til there are only remnants of the threads left that you can grab with an easy out, left hand bits work well but on this with steel corroded in aluminum there is not much chance it will spin out.
Use new studs with copper nuts and use nickel anti seize.

I got it!

The extractor set I could get fast and local was the HF warrior. I was tempted to use right hand cobalt bits, but after the guidance here I recognized that left hand was best.

Of course then I had the extractors that came with the HF set, which weren’t the same as the one I got at my local store.

I drilled with the bushing and it worked good. I used the HF 5/64 left hand bit.

When I tried to go up in size I found that I missed the pilot. Scared by that, I went back to the smaller one to go a bit deeper, and while doing so, it broke!!!! Of course. Probably not even an HF issue…. Just tiny drill bits in horrible circumstances.

So I decided to chance it, knowing that all the rest came out easily. I lubed it all up, and hammered in the smallest extractor.

Put a small wrench on it and I could feel it move a bit. Did the tighten-loosen thing, not sure if I really tightened it given that it would unscrew the tool, but I did it anyway to then put more lube in. And it came out. Phew!!!!!

Now, what about this guy… the only full one that didn’t come out??!?

Of course it’s right behind the oil feed line. So any damage becomes an even bigger undertaking…

Chase and leave it??

Oh, and now I need some quality left hand drills, I don’t think I’ll warranty the HF bit…

 

[Nessism1]

Outstanding work! You are braver than me. I hate EZ-outs, because of their propensity to break off! You have done great, though!

 

[JHZR2]

Outstanding work! You are braver than me. I hate EZ-outs, because of their propensity to break off! You have done great, though!

Thanks! I was sweating it a bit with that little ez out. But I was concerned about stepping up in size without making another bushing (which would have been fine, I guess), or drilling out the one I had.

I did have some confidence because I knew that the others all came out easily… except that one…

 

[Pablo]

The bushing idea is magnificent!

 

[wag123]

And while I’m at it…

Yes or no:

- reuse old studs that came out easily (if I can get nuts off and threads chased)?
- anti seize on the head side stud threads (black oxide steel studs into aluminum head)
- anti seize on exposed side (black oxide steel studs with copper nuts)
- nickel anti seize or something else?

Use New Hardware. Never reuse old exhaust manifold bolts as they can already be fatigued and prone to fracturing. Always install new bolts, studs, and nuts. I use ARP hardware.
Ensure Manifold Flatness. A warped manifold is a major cause of bolt stress and breakage. Personally, I always have the exhaust manifold resurfaced flat by a machine shop.
Apply a high-temperature, metal-fortified anti-seize lubricant, such as a nickel anti-seize compound, to the threads of the bolts before installation.

 

[Trav]

I got it!

View attachment 309811View attachment 309812

The extractor set I could get fast and local was the HF warrior. I was tempted to use right hand cobalt bits, but after the guidance here I recognized that left hand was best.

Of course then I had the extractors that came with the HF set, which weren’t the same as the one I got at my local store.

I drilled with the bushing and it worked good. I used the HF 5/64 left hand bit.

View attachment 309813View attachment 309814

When I tried to go up in size I found that I missed the pilot. Scared by that, I went back to the smaller one to go a bit deeper, and while doing so, it broke!!!! Of course. Probably not even an HF issue…. Just tiny drill bits in horrible circumstances.

So I decided to chance it, knowing that all the rest came out easily. I lubed it all up, and hammered in the smallest extractor.

View attachment 309815

Put a small wrench on it and I could feel it move a bit. Did the tighten-loosen thing, not sure if I really tightened it given that it would unscrew the tool, but I did it anyway to then put more lube in. And it came out. Phew!!!!!

Now, what about this guy… the only full one that didn’t come out??!?

View attachment 309817

Of course it’s right behind the oil feed line. So any damage becomes an even bigger undertaking…

Chase and leave it??

Oh, and now I need some quality left hand drills, I don’t think I’ll warranty the HF bit…

I wouldn't mess with that one, chase the threads and be done with it. Using that small easy out would have scared me a little.
Some left hand bits although they are all in inch sizes. I have some from Dormer Pramet in metric sizes but they are pricey but the inch sizes can get you close enough.

https://knkut.com/drill-bits/left-hand

https://www.amazon.com/Viking-Drill-Tool-87652-Premium/dp/B01C5O9I5G

https://drill-hog.myshopify.com/collections/left-hand-drill-bits

 

[JHZR2]

I wouldn't mess with that one, chase the threads and be done with it. Using that small easy out would have scared me a little.
Some left hand bits although they are all in inch sizes. I have some from Dormer Pramet in metric sizes but they are pricey but the inch sizes can get you close enough.

https://knkut.com/drill-bits/left-hand

https://www.amazon.com/Viking-Drill-Tool-87652-Premium/dp/B01C5O9I5G

https://drill-hog.myshopify.com/collections/left-hand-drill-bits

Thanks for the leads.

It worried me a lot too, but having snapped a bit of bit off meant that I already had issues. Glad it worked out!!! Phew!!!

One other question- the studs I got are longer than the OE. I’d think that extra thread, as long as they bottom out and the thread is low enough to allow torquing of the manifold, would be sufficient.

The ones I pulled were 43. The ones I got are 47. Belmetric has other sizes but no 43mm in stock, and theirs look like the thread length on each side is different.

Dare I install 47mm studs? And, how tight to I install them, finger tight to depth?

Thanks again!

 

[CleanSump]

You can trim the head-side stud threads down a bit with a dremel or other cutoff tool. I've done that, but on a Pontiac. Anti-seize in case you have to come chase some other problem later. You don't want to go through this again.
And yes, the studs don't need to be torgued into the head. Just "finger tight" to depth.

 

[Trav]

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.

 

[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.

Laying them out side by side, assuming the head side is even, I think there will be threads exposed past the manifold. Fingers crossed. Hard to figure out another option, and they’re not cheap if the old 617 OE part is selected - like $34 each x 10!

 

[dfarr67]

I can see if the studs corrode and seize- why do they break like this and are still removable?

 

[Trav]

Have you looked on Amazon? Anything that fits will work fine. A couple of examples..

https://www.amazon.com/dp/B0F3DJ2WZ...4c1223387&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWwy

These are 50 mm..

https://www.amazon.com/dp/B074J3VT1...1115b93f5&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWwy

 

[Cujet]

Great job!!! It is nice to see success. I'd probably try to get that other old one out using heat.

I feared the worst, decades of corrosion and an epic battle. Absolutely wonderful.

 

[Opelman]

Great job. Working on stuff for a living and for fun I've discovered that one can't have enough variety in extraction tools. I really like the straight flute non tapered extractors like the Ridgid 35585 but other styles and lengths live in the same drawer in the tool box.

 

[CleanSump]

Laying them out side by side, assuming the head side is even, I think there will be threads exposed past the manifold. Fingers crossed. Hard to figure out another option, and they’re not cheap if the old 617 OE part is selected - like $34 each x 10!

That's why I said I've trimmed studs to fit with a cutoff tool. That way threads don't extend beyond the manifold and you don't have to mess with washers to shim the nut.

 

[spasm3]

Good job! Glad you got it.
You were brave to use the small easy out. I only use easy outs as a last resort. Most are carbide.
You won't feel them give or flex. It just a sudden snap. Then you are screwed. You can't drill out a broken carbide bit. I avoid them in blind holes.

The one I broke I had to knock out threads and all and rethread to a larger bolt.

Glad you got it!