Exhaust Stud Repair

[mightyspat]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

 

[wore out]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

I would NOT drill oversize except as a "last resort".

I don't think there's likely to be any chance of "extracting" them, you will end up with a broken extractor inside a STUCK stud.

If possible I would drill a 1/8" pilot hole in a piece of 3/8" thick steel that can then be bolted or clamped in line with the center of a stud and a hole drilled into the stud with a 1/8" cobalt bit.

Then, enlarge the hole just enough to leave the threads of the BOLT in the head and "pick" them out of the threads in the head itself.

IF there's a couple of threads exposed "above" the broken studs you can make a "guide" like I did in the post linked below to keep the bit centered.

https://forums.yesterdaystractors.c...-bolt-in-a-pinion-yoke.1629267/#post-10749173

 

[miangus]

A carbide bit would be nice, take extra care and get that starting hole correct. I have used a mill cutter in a die grander to square the end. A center punch helps also. I have had success with welding on a nut. But it sounds like you may be too far below the surface for that to work. After the centering drill hole, I would drill it out close to the correct size apply some heat then cool to break it free, maybe several times. Do not heat it red hot and cool with oil or you need that carbide bit. Go slow and easy. If you must use an easy out, use a square easy out and do not apply much pressure on it. If you get it centered, you can get to where all that remains are the threads. At times metric and numbered drill sizes can help.

 

[rustred]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

if you have no experience in removing broken bolts , not yet exhaust bolts i would have a machine shop do the job. its pretty precise work to get the holes in the bolts drilled straight so they can be retapped. plus its 5 bolts not one bolt.

 

[john in la]

Take it to a shop that knows what they are doing and has experience doing this.

There is a welding rod that in the right hands can weld a new nut to the broken off stud even down in the threaded hole that will allow the broken piece to be removed without effecting the original threads.

 

[560Dennis]

center punch stud , can use a center drill to start out also find best inter of stud.
I use nachi short screw machine drill of below the tap drill size . Drill till it break through the into blind hole .soak with penetrating oil ,heat if safe , easy out of application size for thread .
i ve drilled stainless 10 mm studs out of 4.6 ford truck with ease with these drills when everything else fails .
found the link for you ,nachi

Product Detail | Nachi America

www.nachiamerica.com

If not sure about the procedure , practice drilling the same size bolt on something thats No matter . That you can tell what is involved .

 

[Fritz Maurer]

Find. a new double cut end mill of the correct tap-drill size for the bolts in question. Weld a drill bushing that fits the end mill to a piece of flat steel long enough to reach one of the adjacent bolt holes… the strap should have a slot so you can adjust the aim.
Even if you center punch it perfectly, the twist drill can get a little off center before it bites in real good . Once the center is off, you can never get it back. The beauty of an end mill is you can do some test cuts and move it around as necessary to get dead center.
When you get it right, bore it 90% out with the end mill , then switch to the twist drill of your choice, the same size as the end mill. The reason for this that when the twist drill breaks through, it will grab the end of the bolt and make the threads turn, they will be stuck on the drill and the remains will come out looking like a heli-coil insert.

 

[wp6529]

Recent Abom79 on youtube showed broken bolt removal. While the various guide suggestions migh have some chance of working they have a greater chance of messing up the head. With 5 to remove the chances of success on all without removing the head and using a mill are pretty remote.

 

[BerlinKen]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

Weld a washer to the stud then a nut to the washer. May have to do it a few times. Thats what I did to my AR and finally got it to screw out.

 

[cjunrau]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

if possible lay the engine on the side. heat it up with a torch and let wax run into the threads do this 2-3 times in an hour. wait a dat and do it again. Then drill and use easy out or if you can weld a nut onto it you probably can get them all out. I have done the wax trick a lot and no failures yet. the longest took 4 days of repeating.

 

[glennster]

Take it to a shop that knows what they are doing and has experience doing this.

There is a welding rod that in the right hands can weld a new nut to the broken off stud even down in the threaded hole that will allow the broken piece to be removed without effecting the original threads.

linde sells the stud removal rods. they are expensive!, 444.00 for 5 lbs. here is a link. https://www.lindedirect.com/store/product-detail/x_ergon_electr_m_r_x_tractalloy_3_32/xer332xt

 

[Watthour]

Research "welding broken exhaust bolt" and you might get some ideas.

 

[1948CaseVAI]

Hello Everyone,

Looking for advice on extracting/repairing some snapped exhaust studs...

Case 580D Backhoe

There's 5 separate studs that need removed, all snapped off below the surface of the head. I'm trying to decide if I try to drill & extract them or if I should just drill out oversized and used a thread repair insert?

God knows how long the studs have been sitting in there rusting themselves in place. They were snapped when I bought this thing and that was over 5 years ago. I'm afraid the extractor is just going to snap off. My thought is just skip trying to extract them and skip to just drilling out and use a thread repair insert but I'd like to hear the advice out there first.

Do I need a cobalt or carbide drill bit for this or will anything that isn't chinesium HSS work?

NOT a DIY task. Take it to a shop with experienced staff.

 

[SamV]

I have used the heat and wax method many times. Most of the time with patients you can get it out on your own. Heat around the stud, apply the wax. If it is broken off clean then use the washer/nut combination that is mentioned above. I have never had it fail me.

 

[mechanicfred]

Every time you remove broken bolts, studs or rusted up stuff you learn new tricks. I've been at it fifty years and still learn! Everyone of them acts different. Sometimes a machine shop is the best option.

 

[Hemmjo]

Do you have any good bolt holes? I did this the repair an aluminum engine block on in a jet ski. Someone had attempted the repair and broken a drill off in the stuck bolt.

Bolt the exhaust manifold in place using any existing good holes. Have someone with a lathe make you a steel bushing to fit the manifold bolt holes. The bushing will have a small hole in the exact center. My bushing had a 3/16” hole in it. The use a carbide masonry bit in a hammer drill. The bushing guides the bit and keeps it from sliding off center.

It took some time. I bioreactor out a couple bits but it worked. You would not need carbide if the are just steel bolts.

After you get the small hole you can go to a larger bit. Eventually you should be able to peel the bolt threads out of the hole.

I be happy to make you bushing if you don’t have access to someone.

 

[moresmoke]

Weld a washer to the stud then a nut to the washer. May have to do it a few times. Thats what I did to my AR and finally got it to screw out.

This is my go to method. I have removed many broken manifold studs in this fashion. I clean the end of the stud with a burr or stone in a dremel. Then use a mig welder to build up the stud and add the washer and nut. I usually dap on some wax while it is hot. Then with a wrench, work it back and forth until I can turn the stud out.

Mild steel weld will not stick to a cast iron head.

 

[wore out]

Do you have any good bolt holes? I did this the repair an aluminum engine block on in a jet ski. Someone had attempted the repair and broken a drill off in the stuck bolt.

Bolt the exhaust manifold in place using any existing good holes. Have someone with a lathe make you a steel bushing to fit the manifold bolt holes. The bushing will have a small hole in the exact center. My bushing had a 3/16” hole in it. The use a carbide masonry bit in a hammer drill. The bushing guides the bit and keeps it from sliding off center.

It took some time. I bioreactor out a couple bits but it worked. You would not need carbide if the are just steel bolts.

After you get the small hole you can go to a larger bit. Eventually you should be able to peel the bolt threads out of the hole.

I be happy to make you bushing if you don’t have access to someone.

''I bioreactor out a couple bits but it worked.''

Wondering what that means?

 

[Hemmjo]

''I bioreactor out a couple bits but it worked.''

Wondering what that means?

Ha, it was late, I have no idea how that happened. It was supposed to say “I wore out a couple of bits, but it worked.”

I am going to blame it on my bad typing skills and spell check /word prediction.

Oops.

 

[560Dennis]

Did you get them out ?