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Information please.
I am reassembling an exhaust pipe back to the exhaust manifold flange and can not figure it out after spending much time. I took it apart 8 years ago so I don't remember, and 3 separate LUV manuals including GM Shop Manual have no information on the reassembly order.

I have a 1/2 inch thick donut shaped metal part I think came off the truck that fits perfectly into the bevel in the exhaust manifold output hole. The gasket set had 2 different types of gasket. An asbestos donut shaped gasket much like the metal part, and a 1/8 inch thick narrow metal and asbestos washer shaped gasket.

And there is the free floating flange that goes over the threaded studs retained up toward the top of the exhaust pipe by a swaged in ring in the exhaust pipe.

Which parts do I use and in what order? Thanks

hey there! I have a '79 2wd and changed my head gasket last year (and also the exhaust manifold gasket). Here is what I remember from mine.

There was only one gasket that I got and I believe it was the 1/2 inch one you are talking about. It is beveled on each side. The floating flange shoud be put onto the exhaust pipe (pipe stuck through the big hole in the flange). Next, put the 1/2 inch gasket in between the exhaust pipe and the manifold. The floating flange should now be slid over the threaded studs and this holds the pipe onto the manifold (once the nuts are put on). I don't remember that other part you are talking about (the 1/8 inch washer gasket type thing). Mine just had the donut gasket.

Once it is all assembled and you run the truck for awhile, it will smell real bad as the gasket heats up and burns something off it to make it seal better. Hope this helps!

Anyone else know about that 1/8 inch washer gasket?

it's not a luv, but it might help.

Hey robert. you said ya got a gasket set? Its posable that you got a set that covers a span of years. or similar makes. or something extra for a cali. vehical. you may not need them all. E.

Mystery resolved.

Thanks to those that helped by replying, particularly Dottie, as they gave me the information to think through the problem.

What started this thread is that I thought I had reassembled things correctly, even though it had been 8 years since I disassembled the exhaust. And it ran fine for a few hours, but by then was leaking exhaust big time, so I thought maybe I had assembled it wrong.

It was assembled in the correct order. What I had not done was to properly align the exhaust pipe into the receiving socket in the exhaust manifold. I had relied on tightening down the flange to align it. But all this did was clamp the non-metalic doughnut gasket improperly, and it quickly burned through. Also, the flange nuts were bottoming out on the manifold studs non-threaded area (were there lock washers originally?), so the whole assembly was not totally tight either.

So a new non-metallic doughnut gasket, aligning the exhaust pipe into the manifold socket (quite an undertaking - I had the undo the mounts of half the exhaust pipe system to get enough movement) and putting lock washers under the nuts fixed the problem.

So what are the 3 gaskets I have? The non-metalic doughnut shaped gasket is the correct one. I believe the metal doughnut I also have is the core of the original gasket after the old material was cleaned off, and I saved it because it looked important. And the washer gasket I never could find a use for. Maybe another year or a California model (my LUV is Federal)?

For reference, the assembly order inserted on to the exhaust pipe is:
1. The large free floating flange with holes for the manifold studs. It has two bevels ground into it. The larger bevel should face down the exhaust pipe.
2. The two diameter beveled metal ring that is too small to fit over the swaged in ring in the exhaust pipe. Smaller diameter should face down the exhaust pipe.
3. Non-metallic doughnut gasket.
4. Align and insert exhaust pipe into manifold socket.
5. Slide the sandwich of parts all together, sliding the flange over the studs, and torque nuts to 11 footpounds.

Some gasket sets come with a flat gasket to go between the manifold and a heat riser valve if equipped. The heat riser is emissions related and may not be used in all years, but the gasket set covers a lot of years, so it's included whether it's needed or not. Also, if you bought new nuts for the manifold studs they need to be brass as a regular nut will seize on the threads after a short period of time. Removal will be a pain.

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Been there...done that...lol

Thanks for letting me know about the specialized exhaust nut requirement. Of course, one of the nuts came off and is gone.

Any idea where to find the exhaust nuts? I have had no luck. And this is in Denver Colorado, not that small of a city!

Hardware Stores - Nope
Auto Parts Stores - Nope
Bolt Supply Stores - Nope because it is Metric. The only one to handle Metric and knew what I needed is on several weeks back order for the nuts
Foreign Car Salvage Yards - Nope - but you know they have got to have them just laying around on the ground - sigh
Internet Search - Not enough info listed to see if their nuts are really what I need - still looking

It is Metric 10, 1.25 Pitch, Brass, all metal locking nut

Any ideas of a source, particularly mail order / over the Internet?

Hi Robert!! Good to see another Denver person here, I think this state has lowest per capita LUVs of any state in the country. You probably have tried this but have you checked with AAA Metric Supply???? They are at 1st and Lipan, I use to have to go there when I was working for a furniture company as they are the only ones that had some metric nuts we needed to assemble some of our foriegn furniture. That is the only place I can think of, maybe someone here can dig one up for ya. I wish I could help but I ditched my stock exhaust over 15 years ago.

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RIP R.J.B.

Hi Tilted.

Thanks. Yes, AAA Metric was the one place that knew what I am looking for and their supplys are backordered with ETA several weeks out. I got a lot of snow to plow before then.

And the rest of Denver bolt suppliers have limited metric stuff.

Glad you figured it out!
My exhaust system was held together with soup cans, JB weld, and bailing wire for years and I finally sucked up and brought it into a shop to get a new exhaust pipe from the manifold to the muffler. They custom bent the part from the manifold down the first couple curves (it cost a little extra, but that piece isn't made anymore to my knowledge, I kept my old one if anyone needs it, it is still in pretty good shape). Anyway, after I drove off I noticed it was really loud acouple days later. I checked and one nut was off and the other halfway off. I brought it back and he put two nuts on each stud. That has worked so far (6 months). They were regular old steel nuts. The original nuts on mine were steel and hard to get off and rusted the first time, but I think afterwards, maybe the rust held em on after the head gasket job

So, maybe you can go sweetalk someone at a local muffler shop to sell you some nuts???? Good luck!

PS Post something in the classified section on this site, I am sure someone has some spare ones lying around!

That sucks, cant believe they cant keep a better stock of their product, but I do recall running into the same problem with them.

As for the snow here, did we get some??? I hadn't noticed!! (and now they are saying more this weekend!!! 6 in a row!!)

Got any pics of your truck???? Dont see any on the road here anymore.

Good luck on the hunt, I will be on the look out for ya.

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RIP R.J.B.

I get mine from the auto parts stores such as Autowrong, A lot of auto parts stores have a section with oddball stuff in red packs that are labeled HELP! I've bought manifold stud kits in this section just to get the nuts. I know Carquest offers the HELP section, at least locally.

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Thanks mytmouz for your ideas!

Doing Internet search for "exhaust stud kit" you suggested revealed more options than the "exhaust nut" I was Googleing. It was indeed the red HELP products you mentioned. Little information on the webpage but I ordered them. Local CarQuest has the HELP display, but did not have metric stud kits.

Received the kit and the good news is that the nuts are brass and the correct thread. The bad news is that they are standard nuts rather than locking nuts, and are 17mm across the flats rather than the 14mm the stock originals are. I think I may just be able to get them in there space wise. I am waiting until our Colorado cold snap gets a bit warmer to go crawling under the truck.

I found a turbocharger parts company on the Internet that offers exhaust nuts in the correct thread, and are locknuts, but again with little information. I ordered some and I will let the group know what I receive.

If this does not work, then I guess it is time to go begging at muffler shops.

I can't believe the amount of time and money one nut is causing me. One would think they would be easier to find than this, as I have discovered that multiple import brands use this size.

Usually the new brass nuts are longer. I've always used them with the washers that come in the stud kit. I don't remember any ever backing off after doing this.

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If you think no one cares, try missing a couple of payments...



FIAA!

SFPP!