Steam Driver

Or maybe not; you can tell me.

Since I may (will probably) have to swap the early-model exhaust system on the car for the one with the cat in order to pass emissions, I decided I would go ahead and make a trial loosening of all of the exhaust stud nuts since breaking them seems to be fairly common - at least talked about a lot. That way if one was going to break I could deal with it with the engine out of the car rather than find out about it later and either have to deal with it laying on my back or removing the engine again. So that's what I did - loosen them; eleven out of twelve of them anyway. I didn't have any trouble at all with the first eleven, probably since the car has been sheltered from the elements for so long, and also because whoever installed them used some common sense about tightening them to begin with. But that twelth one, that's another story.

The one in question is the inside nut, front cylinder, right-hand side. This is supposed to be a barrel nut accessible through the access hole in the heat exchange (H.E.). But when I put the long 8mm inhex socket up through the hole it grabbed nothing. That was weird so I got to where I could see the stud and the darned thing had a regular 13mm nut on it!

Well, OK, let's try a 13mm socket. Ooops, that won't work either. It won't fit up through the access hole; O.D. is slightly too large. But by holding it in my hand just right I could get a 13mm socket (1/4-inch drive) on the nut and then run the ratchet with suitable extension up through the access hole. That didn't work either; extension wouldn't engage the socket.

Looking up through the hole from the bottom I could see that the access hole through the shroud was offset from lining up with the stud by at least half the hole diameter, so there's no way it can be used to remove the nut, barrel nut or otherwise - or install one either. The H.E. is not made right (it appears to be O.E.M. however; maybe an aftermarket repop?). So the next thing is to improvise a tool to get it off, as I'm sure the guy that installed the H.E. originally must have done when installing it. What I need is a long, skinny 13mm combination wrench, but I don't think any are quite long enough, so I'll have to get two cheap ones and do some welding it, and also change the angle on the ends so they fit flat with the nut. Hopefully this nut will come off as easy as the rest once I get the tool made.

THEN I'll remove that H.E. and have the access tunnel altered by the sheet metal guy here at the shop so it lines up with the stud like it should. Nuthin' is ever easy, is it?

J richard

Get a long "wobble" extension. Put the socket on the nut and stick the extension through the exchanger like you did previously. The male end of the extension is "football" shapped to allow it to go into the socket at an angle.

Peter Zimmermann

Or find a couple of SnapOn 13mm wrenches that are pre-bent into different shapes. I had a collection of them at one time, but left them with the shop so I can't take pictures of them. Check the SnapOn web site, they must have them pictured...

theiceman

are you trying to save the exchangers or are they rusted out ?
you can always just cut em off with a sawzall to gain access. would be a shame to do all that buggering around then you throw them out after

Steam Driver

I don't think the "wobble" extension will work but I will get one and try it. The offset of the access hole from the stud is quite significant; I don't know if it will wobble that much.

Right now I'm having a wrench welded up, using the box end of one and the open end of the other. I bent the ends last night, then cut the other box end off and am welding that stub end into the open end end of the other one. Making an really long combination wrench. We'll see how that works.

Unfortunately the HE's are not rusted out at all, thus the effort to save them (it). My plan if the wrench(es) doesn't work is to take the torch and cut the access tube so I can get a socket on the nut, then remove the HE and have our sheet metal guy repair it with the tube lined up right.

But all this has brought up another possible issue; see "Thick vs. Thin Flange HE's"

SCOTITUDE

ssi wrench?

Steam Driver

Funny you should mention the SSI wrench; I had a friend of mine in Knoxville mention that to me last night. I didn't know such a thing existed, but he has one. Apparently this "oddity" isn't as odd as it sounds. He's sending it to me to use, or maybe use as a prototype for making my own. The reason for that caveat is that he thinks the SSI wrench is a 12mm, I'm pretty sure the nut(s) on my car are 13.

theiceman

M8 nuts are 13mm unless specified differently.

Steam Driver

Yep, I knew that. I thought it was odd he mentioned 12, but it's been awhile since he's used the wrench.

Actually, he said he never did use it. He was helping another guy in PCA up there put a set of SSI's on a car long ago and he said they fought with it all day long, because of the aforementioned nut situation. But they got it done. Then when they were getting ready to throw away the box/crate they found this funny-looking wrench taped into the top of it . . .

Anyway it's on it's way to me today.

Steam Driver

This is a follow-up to close out this thread.

The SSI wrench my friend sent was indeed 12mm, and the nuts on my 8mm exhaust studs are 13 as they should be. Not quite sure I understand why the SSI wrench would be 12, but it is.

In the meantime I had made a long skinny 13mm wrench and it readily broke the nut loose w/o benefit of heat. So I'm home free there. Unfortunately this wrench won't allow me to get another bite on the nut to move it further, but it is free!

The SSI wrench would work though, so I'm currently making a duplicate of it using a 13mm offset box end. If it works well moving the nut I will probably forgo removing and altering the HE, at least until I need to for emissions reason.

That is all, over and out, etc.