Am I Asking For Trouble \ Playing With Fire Trying To Remove The Exhaust Studs?

[slow&rusty]

Hey Gang - I dropped my exhaust today, everything went nice and smooth.

I was hoping to install new studs while I was in there and tried to remove a few of the exhaust studs by double nutting them and they would not budge, they seem like they are welded to the heads.

I wish there was a way I could use an impact gun on them as the "hammer" action would definitely break them free.

I am worried about shearing them off at the head if I put to much force on them...they seem so brittle...should I just let them be and not play with fire?

-Or- what recommendations do you have or special tools are available to remove these stubborn yet brittle fasteners?

I know quite a few of few have been down this road.

Thanks!
Yasin

[James Brown]

let sleeping dogs lie.

[Joe Bob]

Double nuts and heat......turn to the right then left.....use MAPP gas.

OR leave them be...

[ajwans]

If you got the nuts off OK why do you want to remove the studs? Usually the nuts are frozen on backing the stud out or breaking the stud off when you just want to remove the nuts.

If the threads are OK leave them be and use some anti-seize and/or copper nuts when replacing your heat exchangers.

andy

[dipso]

Usually people use a penetrating oil on the nuts, to free em up. Gravity is working against you on the studs.
I'd be afraid, unless absolutely necessary and you are willing to go further.

[Alan L]

Originally Posted by Joe Bob

Double nuts and heat......turn to the right then left.....use MAPP gas.

OR leave them be...

+1.
It is a tricky decision since you are there already. The more often replaced, the less issues. Eventually they do seem to weld themselves in, as you say, and worse, they get wasted around the head. This weakens them and makes them harder to get out. So, somewhere sometime, someone will have to bite the bullet - but who? If you are planning on keeping the car long term, probabaly the sooner you get them repalced the simpler life will be for you later. Worst option is some/one will break. The heat helps A LOT. The heat goes on the base of the head - around the stud. You are trying to heat the Aluminium around the stud - to free it, not heating the stud - that will just weaken it.
If one does get busted there is a special tool a pelicanite makes/sells (think Pelican may stock them) which by all accounts works very well.
Alan

[HawgRyder]

Personally...I would replace them all with stainless studs.
And then use copper or brass nuts to secure the exhaust.
This will ensure you do not have seized nuts the next time you go in there.
With the heads on the bench....lots of options for removal...and room to work.
My $.02
Bob

[Joe Bob]

Pelican Parts.com - 4pc 1/2"-Drive Stud Puller/Socket Set

[James Brown]

if you do break them off, a cool tool is the EDM. some are portable and they come to you or you have to remove the head and take it to the shop. here is a write up on the procedure.
Pelican Technical Article: EDM Broken Bolt and Stud Removal
it's in the tech articles on this site.

[Geronimo '74]

Originally Posted by HawgRyder

Personally...I would replace them all with stainless studs.
And then use copper or brass nuts to secure the exhaust.
This will ensure you do not have seized nuts the next time you go in there.
With the heads on the bench....lots of options for removal...and room to work.
My $.02
Bob

+1!
With the heads on the bench, i don't see why you wouldn't.

[skrufy]

My 2 cents: broken exhaust studs are a major PITA IMO and experience. Trying to drill them out straight for a helicoil or time cert , then tapping the new hole is a ton of work. If your drill starts to go off center, then you are chewing into fresh aluminum. I had seen a drill guide that fits over and attaches to the other exhaust stud so that you are drilling correctly- angle and position. Don't know who makes it though......

If the engine was out and inverted on a stand, you could try PB Blaster, a great penetrating and catalytic lubricant to hopefully free up the studs- otherwise, as commented above, gravity is working against you trying to chemically free them up for removal.

I personally would leave them alone. Run a die over the studs to clean up the threads, use an anti-seize lube like Permatex, fresh gaskets and nuts, and you are home free and onto the next project.

If you must remove them, I'd contact a reputable engine 911 builder, or some of the race car guys, to see what they suggest. Pick up a copy of Pano or Excellence and thumb thru the pages- a bunch of guys are listed. In the Phoenix area, call Turbocraft or Patrick Motorsports- both of those guys can give you great advice.

Let us all know please how you make out. You are choosing a path- maybe?- that most of the rest of us fear to thread. I certainly would not use a hammer drill or impact wrench- I think you will shear those bolts before you know what hit you. Good luck!

Tim

[Alan L]

"I had seen a drill guide that fits over and attaches to the other exhaust stud so that you are drilling correctly- angle and position. Don't know who makes it though......"

This is the tool I was referring to. Can find you a link to the guy if you decide to. Bought one a few months ago - knowing one day I was going to deal with this issue again - maybe. At the point you are at, I have always replaced the studs and dealt with the issue at that time. The tool has had excellent reports.
My option is the opposite, (but the same to posted above) - I use regular studs, but stainless nuts. They never seize. But the stainless studs may work better in the heads too.
Alan

[JJ 911SC]

Originally Posted by joe bob

pelican parts.com - 4pc 1/2"-drive stud puller/socket set

NLA but I used the Sears kit with success on an exhaust stud that was broken and had no room for a straight trough puller.

[slow&rusty]

Originally Posted by Alan L

+1.
It is a tricky decision since you are there already. The more often replaced, the less issues. Eventually they do seem to weld themselves in, as you say, and worse, they get wasted around the head. This weakens them and makes them harder to get out. So, somewhere sometime, someone will have to bite the bullet - but who? If you are planning on keeping the car long term, probabaly the sooner you get them repalced the simpler life will be for you later. Worst option is some/one will break. The heat helps A LOT. The heat goes on the base of the head - around the stud. You are trying to heat the Aluminium around the stud - to free it, not heating the stud - that will just weaken it.
If one does get busted there is a special tool a pelicanite makes/sells (think Pelican may stock them) which by all accounts works very well.
Alan

Thank you all for your responses, I appreciate it.

Exactly my thoughts Alan, Tim and Bob! I want to replace my original studs now 23-years old (car is an '89) with new stainless studs and copper fasteners. This is a car I plan to keep for a long time (in my 7th year of ownership right now) and figure now is the time..like you all said someone has to do it! I am nervous fearing the worse but will take my time and cross fingers and toes.
Thank-you for the tips and tricks. Is MAP gas hot enough?
Regards - Yasin

[Shaun @ Tru6]

I used two methods on a 170K mile 3.2 where the studs were badly rusted away.

For the "easy" ones, I used a proper stud extractor with a long 1/2 inch drive ratchet and mapp gas. Go slow and they'll come right out.

For the ones I felt the extractor was not working, I welded nuts to the studs just above the head surface. These then came right out. The heat cycle of the weld (let cool, then heat the head) may have contributed to the success on these. Long half inch drive and deep 13mm impact socket made a difference.

Good luck!

[Jesse16]

Sounds like you've made your decision but I'd leave them alone. If the threads look OK, the steel is fine and they've lasted this long sooooo, why change ? They aren't something that usually fails anyway.

[don gilbert]

I always soak them for a while, then take a long punch and give them a few good whacks staight on with a hammer. Helps bust up the rust. If they break, and some usually do, the studs are pretty soft and easy to drill out. (compared to dilavar head studs) On my own personal car, when i had the engine out at one time, I drilled em all to 10 mm and used hardend allens. Can tighten the heck out of them. I all way get the pre-75 gaskets from pelican, lots thicker and seal better than the 75 up thin copper ones.

[Elombard]

I am thinking wait until you have the motor out at some point?

[larrym]

This topic is discussed in several other threads - "leave 'em alone if you can" is the best advice

- but if you can't, be prepared to buy the tool

I just had to drill out a couple on my 3.2 - they are NOT "soft" (maybe softer than dilavar, but still damn hard) - they will significantly resist a common hardware store variety all-purpose cobalt drill bit and wear it out real quick

- buy Industrial Quality HSS bits - (you can use RH bits for the 3/16 size initial pass)

I bit the bullet and bought the Stomsky tool from Pelican - it works great, but i did break a couple of the drill bits in the process

- well worth the $300, (read the tech post about it)

buy some spare Industrial Quality HSS LH left hand bits - not easy to find in the local stores

i figure i will need it again someday

L

[Joe Bob]

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