Turbo gasket and stud removal.
 

After a recent track event I realized two things.

1.) I screwed up bolting my turbo to the manifold by not replacing the washers
2.) I blew the gasket between the turbo and the exhaust manifold

I used a USB endoscope camera and found this little guy (a piece of the metal gasket) poking out:


https://cimg4.ibsrv.net/gimg/www.evo...72e637ff85.jpg

My plan was to remove the two studs, remove the bad gasket, slip in a new gasket and then use four new OEM MHI bolts and eight new OEM MHI belleville washers.

The plan worked so flawlessly that I decided to make this post.

Steps were as follows:

1.) Remove strut bar 6x 14mm nuts and 2x 14mm bolts in the center of the bar
2.) Remove exhaust manifold heat shield 5x 10mm bolts
3.) Remove heat shield carefully as to not bend it
4.) Remove the two turbo bolts closest to the radiator and four washers
5.) Remove the two turbo nuts from the two studs closest to the firewall and four washers
6.) Please a rag under the two studs to soak up the spray your about to do
7.) Spray PB Blaster on the two studs every 1.5 hours for 6-8 hours (don't rush this)

Next your going to need a 10mm 1.25 pitch nut that is strong and dimensionally bigger than the factory nuts. Autozone had exactly what I needed. The size is 17mm and it is grade 10.9 so it can take some abuse:

https://cimg6.ibsrv.net/gimg/www.evo...25d89a5fa6.jpg

8.) Your going to have to shave down a 17mm socket so that it fits without interference with the exhaust manifold. There just isn't much room there.
9.) Grind and shave down one of the factory 10mm nuts so you can get the 17mm shaved down socket over it.
10.) Finger snug down the larger nut first and then the smaller one. Jam those two puppies together using a 17mm wrench and a 14mm socket. I was able to fit a full size 17mm wrench on both studs, so you can too.

Here is what it looks like:

https://cimg7.ibsrv.net/gimg/www.evo...0739c040a8.jpg

11.) Using a torque wrench apply (counter clockwise fool!) LESS THAN 80ft-lb to the stud. You do NOT want to break it.

This is where I was lucky and the stud just backed right out. Both of them. You can bet I am going to be buying PB blaster again in the future.

https://cimg6.ibsrv.net/gimg/www.evo...22c6f14d96.jpg

Had the torque wrench hit 80ft-lb without moving the stud my plan B was to:

1.) Apply heat with a propane torch ($17 at home depot) to the stud and repeat 80ft-lb torque removal
2.) Apply an impact wrench to the stud and repeat 80ft-lb torque removal
3.) Re-apply PB blaster every 1/2 hr for 2 more hours and then try all over again

Now.. When you reassemble this it is VERY IMPORTANT that you use new belleville washers from MHI.

This is what keeps the turbo from working loose and blowing a gasket, that little gap between the washers is the available "spring" that the pair of washers provides for expansion and contraction:

https://cimg1.ibsrv.net/gimg/www.evo...fcaf87f875.jpg

Autozone has a 1/2" drive angle gauge for ten bucks, so I picked one up.

1.) Apply high-temp anti-seize to the bolts and some of the bolt surface area to reduce friction.
2.) Torque to 22ft-lb and then rotate an additional 65 degrees +/- 5 degrees

Those last two steps are very important. Torque ratings are different for dry or lubricated bolts. With brand new anti-seize on the bolts the bolts are considered "lubed" and the torque being applied to the actual assembly is more true. The additional 65 degrees basically pre-loads the belleville washers.

If your going to do some autocross or track duty you may want to repeat the "lube" and torque procedure again before you really work the car over.

My local Mitsubishi dealer says they "snap turbo studs almost every single time, regardless of mileage". My only guess is that they just don't have the time for a penetrating lubricant to do the work for them.

Good Luck Guys!


~Jaraxle

Wrote this to help someone out, over 300 views and zero thanks!
What the heck!?

Peace out

Excellent How to post. This is some really good information, wish I would have found it sooner! Do you have any additional pictures of the shaved 17mm socket? Is it a 12pt or 6pt socket? Also, are you able to provide measurements of how wide the socket is on the shaved end?

P.S. Thanks was given earlier :)

I would not attempt this with a 12pt socket. 6pt is recommended. However, it would be a BRAND NEW nut so you MAY have success without using a 6pt. I can post additional pictures of the socket. Basically all you need is a grinding wheel or a dremel or and work it until it fits over the nut with interfering with the exhaust manifold. I would have measured the outer rim of the socket put my micrometer gauge is somehow broken electronically and I need to buy a new one.

Good post. Every time my turbo comes off it gets all new hardware (bolts, nuts, washers, studs can stay) and gasket for turbo-manifold connection.


On the X, IF a stud breaks, removing the manifold to have access to the broken stud is pretty easy.

Several ideas during my installation, may be helpful
1. crowfoot wrench (e.g. https://www.harborfreight.com/7-piec...set-94427.html) + long break bar may help, one of my bolts come off with just this setup and two nuts from the engine side.
2. if unfortunately the stud broke, it happened when I worked on mine, use a flat screw driver to pull the manifold upper a little bit. It's likely to be able to get a 0.5 - 1 in gap, and the stud can be cut by using cutting disc with drill adapter on a regular drill (e.g. https://www.homedepot.com/p/Avanti-P...B&gclsrc=aw.ds). Then you will have some extra threads to try the double-nut way.
3. Only cobalt drill bits work on the stud.
4. If unfortunately the threads were broken during the drilling, use a longer bolt with a nut on the other side, it should just work fine or even better than the stock setup.
5. If installing a map cast exhaust manifold, the longer bolt needs to be somewhere around 5 in.

Thanks for the info. Its well presented.

I meant to ask this sooner but, why did you remove the studs in the first place?

Per first post:

"My plan was to remove the two studs, remove the bad gasket, slip in a new gasket and then use four new OEM MHI bolts and eight new OEM MHI belleville washers"

Fastest way without having to remove the turbo or manifold.

Lol, I did read that but it didn't click.. :spin: