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msavides

How to Replace broken exhaust studs

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Here is the well needed write up on how to fix broken exhaust bolts. Photos are here

http://www2.snapfish...165/t_=88532165

 

http://s212.beta.pho...n exhaust studs

 

 

click view now to see pics

 

Almost forgot the most important step. PB Blaster and lost of it, and time.

 

First off this was done on a 1991 Nissan pathfinder with a 5 speed manual transmission and a 3 inch body lift.

 

* First thing to do is remove the exhaust shields off the exhaust manifolds.

 

* Next remove the collector bolts from the exhaust manifold.

 

* Then remove exhaust manifold bolts. Some people say that using an impact wrench on the studs works better for removing the studs, I am not so sure that is a good idea, I never tried it, I used a ¼ drive ratchet to remove them so I could better feel the breaking point, Not sure it that work with much success either.

 

I ended up with 3 broken in the end 2 of which were broken from the start. If the stud breaks in the middle then you can try grabbing it with a pair of vice grips or use a tool for removing broken bolts. If the bolt breaks flush with the head you will need to drill them out.

 

* To drill them out you will need a right angle drill and some bit extractors.(see tool link list below) Do not try and go with cheap bolt extractors. They will break on you and leave you in a worse situation.

The most important thing when drilling it to stay in the center of the bolt. Take your time. Do not push hard let the drill do the work and use some oil while drilling. If you go off center you will end up drilling out the head and mess up the threads. If you do this a little bit then you will have to go with a helicoil, but only if you are slightly off center. If you are way off center it is new head time.

The extractors I used drills the stud in reverse and in some cases you can have the stud unthread while you're drilling (this is a good thing, however none of mine were that generous.)

 

* Once you drill the stud all the way through (you will know when you have) slide the extractor up and lock it in place and then put your socket wrench (I would not use the drill for this) and begin to unthread the stud. If all goes well you will be putting new studs in, in no time.

 

* If you drill off center (I had one) you can try to extract with the same method as a above, pay attention to where the extractor is biting. If it bites into the head (pinning the stud against the head) you will break the extractor. If you notice this happening stop, remove the extractor and go buy a Helicoil.

 

*The instructions for the helicoil will be on the package. It basically tells you to drill with the appropriate size drill bit (do not substitute the drill size. The drill size has to be exact. It will be larger than the stock stud hole size. This is normal) My stud came out while I was drilling it for the helicoil. Once it has been drilled you must tap the head.(do not over drill or you may hit a water jacket or worse, also make sure you are not drilling off center or the same may happen)

 

*Tap the head with the helicoil tap turning 2 to 3 turns while adding oil then back out the tap all the way to clear away the cuttings. Spray brake parts cleaner or carb cleaner to clean the hole out, then start again with the oil and go 2 to 3 turns more past where you last were and then repeat until you get to the bottom. Then thread the helicoil in with the supplied tool. When finished break off the tab at the bottom of the helicoil.

 

I typed this out of memory. I did this 8 months ago so I may have missed some key steps. If you spot them please let me know so I can edit the document.

 

Mark

 

 

Tools

 

http://www.sears.com...=bolt extractor

Edited by msavides

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msavides, did you use the 300zx bolts for replacement? Where can one get those?

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msavides, did you use the 300zx bolts for replacement? Where can one get those?

 

 

Actually I used these. I did not want the bolts to ever get loose and start leaking. They have been rock solid. I also used some anti seize on the threads and reduced the tightening torque.

http://image.mustang50magazine.com/f/29293762+w750+st0/m5lp_1008_21_o+2002_ford_mustang_gt+trick_split_lock_header_bolts.jpg

 

 

 

Breslin the company that made them went out of business. However they were most recently purchased by percy's. do a search for split lock bolts on ebay or on google. You want the size: LS-6 8mm-1.25x25mm

 

They are pricey but IMO well worth it. You can find deals on them if you keep looking on ebay. I just bought some on ebay for $21 shipped.

 

 

 

Update: I did this 5 years ago. I have not had to touch the bolts since initial tightening. I did not have to re torque them at all even after the the initial install

 

It is a shame these bolts are no longer available. If you google search them you will find lots of people raving about them . Again Search ebay you can still find them every so often.

 

 

 

 

Mark

Edited by msavides

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WHAT A F#%KN NIGHTMARE!!!!

I had 1 broken stud on the driver side and 1 broken stud on the passenger side to begin with. After removing the manifolds, I had 3 broken on driver side and 2 on the passenger side. I have a 95 2wd without a body lift and lemme tell you...this job was a bitch!

All 3 studs were drilled and extracted on the driver side using an electric drill and a 90degree drill chuck from Home Depot. Although it was a PITA to get in there, I finally got in and got them extracted.

However,on the passenger side, I had to "fashion" a drill extension to the drill bit to drill the studs on the passenger side. One went just fine, just as easy as the driver side studs. Now on to the very last broken stud.

Unfortunately, the hole I drilled did not sit center of the broken stud so the extractor ended up breaking off into the broken stud!! UUUGGGHHH!!!

I then proceeded to drill out the broken extractor...NO DICE! Theres just not enough room for the tools I was using, so I decided to let that one alone. I have read of others running into this same problem and having to leave 1 broken stud behind. After all this fighting (not to mention the small fortune in tools for this particular job), It just sucks not to have ALL new studs for the exhaust! Oh well, If I ever have to pull the engine for some reason I guess Ill get it out and replace it then.

Thanks to all for the write up, hope others have better luck than I did on the passenger side!

 

Maybe...Just,maybe...the new gaskets and bolts will seal regardless of the 1 missing stud and I wont have an exhaust leak anymore!. Wish me luck!

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You'll still have an exhaust leak, it will just be less pronounced and you'll hardly notice it, at least in comparison to before.

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Your absolutely right! I just finished putting the wheels on her and fired her up. She's a whole lot more quiet than before, but still a slight leak when accelerating. I can live with it until time for an overhaul(when and if). It'll be easier to take care of whilst the motors out. :FartExplode-vi:

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uhhh I have to do this job now.. OMG I don't want to do this, I just know it's going to suck big time. :thumbsdown:

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Good luck slash! Take your time...dont rush, and you should do fine. Oh, and lots of :coffee!: !

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Oh geez, Nice video!!

I was just about to start a new thread on this, guess I'll just add to this one.

I replaced all my studs the other day while I had the head off. Here's how I went about it, as I'm too cheap to buy a real extractor.

 

If you've got a body lift, or even just rip off the wheels and tear out the inner fender lining, you should have enough room to do this without pulling the motor out/apart :)

(sorry in advance for poor cell phone pics)

 

First thing- I used a center punch to put a dent in the middle of the stud to stop my drill pit from walking

DSC00067.jpg

 

 

Next- drilled a 7/64" diameter hole (I used Cobalt bits from Mac Tools) first using the smallest bit in the set, followed by a slightly larger and then finally the 7/64" bit

The factory bolts are soft, but you'll still want to step up in sizes

DSC00068.jpg

 

As shavings built up around the hole, I used a small magnet and a blow gun to clear them

DSC00069.jpg

 

The hole should look something like this, and doesn't need to be much more than an 1/8 ~ 1/4 inch deep

DSC00070.jpg

 

Next, I hammered in a T15 Torx socket until the 'teeth' were completely buried in the broken stud

a screwdriver style with a set of vice grips on the handle or even a Robertson will work too.

I prefer the torx as there are more points of contact with the stud

DSC00071.jpg

 

Once that bad boy is buried good n deep, use a ratchet or any other available means to twist until it's out

DSC00072.jpg

DSC00066.jpg

 

Once all the broken studs are out, be sure to have a good supply of M8 grade 8 studs to go back in so you don't have this problem again

Crappy factory studs left, Awesome grade 8 studs right

DSC00073.jpg

Grade 8 will always be blackish in color

DSC00075.jpg

 

Then just clean up your manifold or header to a mirror finish (if installing new, they should already be clean and ready)

and bolt it on. If reusing the stock collector, now would be a good time to replace studs with grade 8 M10 studs.

I had to use a TON of penetrating lube and a good set of vice grips to get the factory ones out

DSC00076.jpg

 

Then just throw on your new gaskets, bolt it up, and good to go :)

 

I re-tapped all the holes before installing the new studs. Not really a necessity, but it makes life a whole lot easier when installing the new studs. Tap and Die sets can usually be rented for free at your local auto parts store.

 

 

I know this is actually a WHOLE lot harder when it's all still in the truck and you have no body lift

but... least there's some pictures to give you all a basic idea of how to get it done

Edited by Manifesto

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Good luck slash! Take your time...dont rush, and you should do fine. Oh, and lots of :coffee!: !

 

 

&%#€!! DAMMIT!

I found one broken stud in the drivers side, it apears that the previous owner fixed the passenger side (it has black grade 8 studs)

The broken stud is the first one (from front to back)... it's imposible to reach!! There's a team of mechanics trying to fix it..

if not.. gasket, silicone and faith... I refuse to take the head out just for a f***ng broken stud.

The good news is that the exhaust system is coming along nicely.

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i have to do this also, but i think i am just going to pay my mechanic to do it :D i am sure it wont be much... i normally can buy the parts and he charges me a decent amount for labor($50/hr or so)hell he's going to replace my "leaking" gas tank for $135 which is a PITA and the tank is only going to cost me $115.

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i have to do this also, but i think i am just going to pay my mechanic to do it :D i am sure it wont be much... i normally can buy the parts and he charges me a decent amount for labor($50/hr or so)hell he's going to replace my "leaking" gas tank for $135 which is a PITA and the tank is only going to cost me $115.

 

What's holding your tank in, hopes and dreams? :rofl: Sorry just picturing the pics of your frame. No tank would be the most oportune time for you to jump on that too! (Back on topic now! Sorry!)

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also I discovered when my buddy was fixing his header leak on his 84' Dodge the other day

there's some high temp copper silicone that is AWESOME instead of a regular gasket

-- he replaced the gasket and it STILL leaked, so he globbed on some high temp copper silicone (good for 378F) bolted it up good n tight, wiped off the excess and it worked beautifully :)

 

 

as for drilling those studs with it all in the truck

- a 90 degree air drill works pretty good for that

may be able to rent one free at you local auto parts store

 

pulling the heads is definitely a bigger pain... I've had mine off for over a month and... I kinda forget where all the wires go >_<

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The stud won... =( couldn't get it out. The previous owner had also tryed.

I'll just leave it like that, with good gasket, good high temp silicone and a lot of faith.

 

Crappy Studs 1 - Slashjt 0

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argh yea... doesn't work EVERY time

sometime all you can do is drill it out and re tap the threads and maybe stick in a heli coil :/

 

I'm not sure how well it will seal missing a stud, but definitely try globbing on a ton of the high temp copper silicone stuff

worth a try :crossedwires:

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argh yea... doesn't work EVERY time

sometime all you can do is drill it out and re tap the threads and maybe stick in a heli coil :/

 

I'm not sure how well it will seal missing a stud, but definitely try globbing on a ton of the high temp copper silicone stuff

worth a try :crossedwires:

 

Other dude tried and he did it!!! the freaking stud is out :D

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argh yea... doesn't work EVERY time

sometime all you can do is drill it out and re tap the threads and maybe stick in a heli coil dry.gif

 

I'm not sure how well it will seal missing a stud, but definitely try globbing on a ton of the high temp copper silicone stuff

worth a try viannen_09.gif

If your gonna heilicoil You might as well take it up a size and use VG33 studs (10mm) The stock mainfold (and aftermarket headers) will fit over them fine and you will never have to worry about them again.

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Anyone know the pitch on the VG33 10 mm studs?

 

The answer is 1.25 mm. The studs seem to be about 38 mm long (maybe supposed to be 40?) with 10 mm of thread on the block side and 20 mm of thread on the manifold side. The washers are thick and the nuts have a flange on them. Probably none of this is critical though.

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Thanks for the information though, someone will need it. A simple FYI, the WD21 stud thread pitch is M8x1.25.

 

B

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Thanks for the information though, someone will need it. A simple FYI, the WD21 stud thread pitch is M8x1.25.

 

B

 

My pathfinder is 8 x 1.25 like B said except 4, 1 hole but thats because of the previous owner drilling and tapping that 1 hole up to a 3/8" hole. I really dont know why it was done it makes it a pain to work on that side.

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My pathfinder is 8 x 1.25 like B said except 4, 1 hole but thats because of the previous owner drilling and tapping that 1 hole up to a 3/8" hole. I really dont know why it was done it makes it a pain to work on that side.

 

I'm trying to decide if I should tap to M10x1.5 (the standard pitch, doesn't match the VG33) and just cut up some grade 8.8 M10 redi rod. This would be way cheaper than buying the VG33 studs. But I might just leave things as is (with the stock M8 studs) and change things later if it causes a problem. Of course this is so much easier now with the engine out...

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An option here - go to a junkyard and remove grade 8 exhaust studs until you get your fill. The yard may not even charge you.

 

Summit Racing sells 10 for ~20 bucks.

Ebay

Edited by 2milehi

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I did this a while ago and don't know if any of this will help.

-Go through the wheel well after taking the wheel off. this gave me sufficient room

-Use a Punch to get your hole centered before drilling. this give you a hole for the bit to rest in(no walking)

-Use a left handed drill bit (cuts when turning left)

-Soak studs in PB blaster (or similar product) for at least 24 hrs prior to starting

- Used the torque from the drill on the extractor it works well....

-As always go slow, use a lot of lube, and good luck

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