Broken exhaust manifold flange studs

[silky28]

hey all. Not sure if this is the right place for this...

Anyhow, as some may know, last week i replaced the transmission in my 03’ ‘hoe z71 in my driveway. Long story short, the exhaust has been a nightmare: the studs from the year-pipe to muffler snapped - 3 of the 6 studs from the exhaust manifold to the y-pipe snapped off - and then I found that 3 of the exhaust manifold bolts had the broken bolt head issue.

The y-pipe to muffler issue is no biggie. I knocked the studs out and replaced with stainless hardware. The broken exhaust manifold bolts was also easily fixed by welding nuts to the broken bolts. But I am having lots of trouble with the exhaust manifold t y-pipe studs.

So far I have tried heat with vice grips with no luck.

I have tried welding a bit into the broken stud but either the stud snaps again or the weld gives way when I torque them.

Finally I have tried cutting the stud flush with the flange and either welding a bit or bolt to the broken end, or making a glob weld I can grab with vice grips - nothing has worked.

What should I do here? I don’t have a torch that can cut the stud out. Should I just drill it out? If I drill it out do I have to retire as the flange or can I just replace that with a bolt and a nut; could I weld a bolt onto the flange so that I don’t have to hold both sides while tightening?

I have contemplated taking them to a muffler shop but I am sure it will cost at least $100. For $100 I would be more inclined to replace them either with aftermarket factory replacement or some cheap short tube headers.

 

[Dantheman1540]

I'd drill them out and replace them with a bolt, lock washer, and nut.

I just did a bunch of exhaust work and soaked everything with this stuff I call it creep oil. We use it on aircraft and it's by far the best penetrating lube I have found for getting stuck stuff unstuck. Obviously too late for that now but that's my suggestion for next time.

 

[Larryjb]

There are bolt-on repairs for the broken studs. It is a type of bolt on clamp to keep the exhaust manifold clamped to the head. It really does work if you are unable to remove and replace the bolts. I've forgotten the name of the thing, but some others may remember.

I would say it actually works well enough that I wouldn't bother to take it anywhere to have the bolt extracted. If you have welding techniques, you can weld things onto the stud to remove it, or there are the extractors you can buy and use and hope they work, but you have to get it in the center, and there's not much space to work. I used one of these clamps until I had to remove the heads to replace the infamous cracked head.

 

[wjburken]

There is a guy on here selling one. Not sure if its for the side you need but should get you on the right track to finding what you need.

I think @915_Tahoe found one for his that was for the opposite side this one was for. He ended up removing the head and extracting the bolts I think.

https://www.tahoeyukonforum.com/threads/dorman-917-142-exhaust-manifold-clamp.119018/

 

[zmann96]

I used those bolts on both sides when I replaced my exhaust headers. They make a few different combinations. type will fasten one end of a side and the same fastener will work on the other side opposite end. There not that expensive and solves the aggravation of trying to get the bolts out. https://www.amazon.com/Exhaust-Manifold-Bolt-Repair-Trucks/dp/B089QL3JSX

 

[the_tool_man]

hey all. Not sure if this is the right place for this...

Anyhow, as some may know, last week i replaced the transmission in my 03’ ‘hoe z71 in my driveway. Long story short, the exhaust has been a nightmare: the studs from the year-pipe to muffler snapped - 3 of the 6 studs from the exhaust manifold to the y-pipe snapped off - and then I found that 3 of the exhaust manifold bolts had the broken bolt head issue.

The y-pipe to muffler issue is no biggie. I knocked the studs out and replaced with stainless hardware. The broken exhaust manifold bolts was also easily fixed by welding nuts to the broken bolts. But I am having lots of trouble with the exhaust manifold t y-pipe studs.

So far I have tried heat with vice grips with no luck.

I have tried welding a bit into the broken stud but either the stud snaps again or the weld gives way when I torque them.

Finally I have tried cutting the stud flush with the flange and either welding a bit or bolt to the broken end, or making a glob weld I can grab with vice grips - nothing has worked.

What should I do here? I don’t have a torch that can cut the stud out. Should I just drill it out? If I drill it out do I have to retire as the flange or can I just replace that with a bolt and a nut; could I weld a bolt onto the flange so that I don’t have to hold both sides while tightening?

I have contemplated taking them to a muffler shop but I am sure it will cost at least $100. For $100 I would be more inclined to replace them either with aftermarket factory replacement or some cheap short tube headers.

I'm about to tackle exhaust manifold bolt replacement on mine. I see several have offered solutions for broken manifold bolts. But if I understand your post correctly, you dealt with that. Your issue seems to be the studs that connect the manifold to the Y-pipe, correct? Did you get it figured out? I haven't looked closely at that connection. Do the studs screw into blind holes in the manifold? Or are they through a flange where they can be pounded or drilled out?