Exhaust Manifold to Engine Bolts

[Dr. Swagmor]

Hello everyone,

Recently purchased my first Ranger knowing that it was going to need some work. We believe it is either a head gasket issue, cracked head, or something related to the valves. We are working towards removing the heads to take them to a shop to get serviced and pressure tested.

We have nearly everything removed and the last piece of the puzzle that remains is the exhaust manifold. We broke two of the OEM bolts that fasten the manifold to the head and fully removed one of the bolts. To get the clearance to remove the head, we are pretty confident that we need to remove the remaining bolts (they will all be replaced during the rebuild). For the remaining 7 bolts, we cannot figure out how to remove them from the head. I looked for a 4 or 8 point socket and they don’t make them that small. I will include the picture that I have, the nut is still on in the image but it is currently removed as well as the pushrods.

Any advice on how to remove the remaining bolts or other ideas to allow the manifolds to move enough to give the required clearance? We have some basic mechanic skills but this has been a big undertaking for my buddy who’s been helping and myself.

It is a 2000 Ranger V6 4.0 OHV with a manual transmission

 

[SenorNoob]

First welcome to TRS!
Show us the rest of the project.

I'm gonna suggest a wrench on that. Boxed end if you can. Very tight fitting open end if absolutely necessary.

 

[Curious Hound]

I looked for a 4 or 8 point socket and they don’t make them that small. I

Looks like a regular 6-sided hex nut to me. Maybe I don't understand the question.

 

[Dr. Swagmor]

Thank you for the response, I have some better pictures to better explain my issue. The hex bolts came off mostly no problem, some seized and snapped the bolts. My issue is how to remove the bolts or how to move the exhaust manifold enough to get enough clearance to remove the heads. I couldn’t even find a wrench small enough to fit the square peg end and I can almost wedge a 7/36s socket but I don’t have enough grip to crack them off

Last image is the current state of the teardown.

 

[SenorNoob]

Oh, your looking to pull the studs...

There are tools for that too. Lots of people put 2 nuts locked together on them but that isn't exactly right either.

https://www.oreillyauto.com/detail/c/performance-tool/performance-tool-stud-extractor/pfm0/w83203

No idea how it works. I've never used one...

 

[Roert42]

Studs is the word you are looking for.

 

[Roert42]

You could put two nuts on the stud and lock them together, then use that to turn out the stud.

Or

Stud extractor.

https://www.harryepstein.com/products/1952-wright-tool-stud-extractor-nos-x79?srsltid=AU7gw4WLkaNGwwLYg0jpvoRhD4Q5as8K6qqXjAs4HKJXbi40OL58pOMC

 

[Dr. Swagmor]

Interesting and thank you! I have been to oreillys, auto zones, and a ford dealership to get any help and had no answers until this post. I don’t have any impact drivers so I will spray with rust off and try the double nuts idea. I probably wont have an update until Sunday or Monday.

I looked into replacing the studs and from what I can find, they are obsolete and not produced anymore. I’m hoping to not have to take these off for a while after this project but is there a recommended replacement that would be easier to remove in the future?

 

[Curious Hound]

Quite often, people remove the manifolds from the engine bay before removing the heads. Of course, there are several ways to do the whole project.

Stuck exhaust manifold studs or bolts are very common and that's the nature of the beast. The repeated heating and cooling cycles with humidity in the air, the curvature of the earth and leap years, they get rusted in there pretty snug. For finding and ordering new ones, you just need to know the thread size and length and quantity. Then you can order bolts or studs as you wish. You don't have to order bolts with the exact label "2000 ford 4.0l exhaust manifold". Just find a set of (for example) qty12, 5/16" x 2.5" exhaust manifold studs with hex nuts and lock washers. ARP is a common brand. I ordered new ones for my 5.0l through Summit racing. If you order studs, you can order them a little bit longer and the nuts will just tighten down where they need to be. Some of my bolts were a little bit too long. I cut them down so they wouldn't bottom out in the holes before I reached the proper torque.

You will also want the clean the threads in the holes. They make tools called thread chasers for that. I used a tap. But there are some who will say a tap is the wrong tool.

 

[Roert42]

Studs are the best replacement. Could use bolts though.

With studs you have more than one way to remove them. With bolts, if you bust the head off it’s game over.

Worse case you can cut them off and have a machine shop extract them.

Replacement studs are available. They are M8x 1.25mm thread.

 

[Curious Hound]

With studs you have more than one way to remove them. With bolts, if you bust the head off it’s a stud. game over.

FIFY

 

[RobbieD]

You might just find a real socket made to fit the stud end. I know that, at least years ago, Snap-On made sockets to fit those.

I've got one somewhere. I think that they were sold as "shock stud sockets", to fit the piston rod end on shock absorbers.

 

[Dr. Swagmor]

Really appreciate all the advice, unfortunately I need to wait a little to put them into practice but I will provide an update. Went into this having only replaced spark plugs in a Mini Cooper so this is a big project. TRS has been very helpful along the way and I’m excited to get it working right.

 

[Roert42]

I thought about rocket sockets too, probably a 7mm one would fit well on an 8mm stud.


Exhaust manifold’s is like one of the hardest things to remove on an older vehicle. Even in moderate climates the heat cycles can cause everything to rust and seize.

 

[pjtoledo]

double "D" shock socket. they are measured across the flats.