My exhaust manifold was cracked almost completely around the base of one of the tubes. I got one off of craigslist, that the guy said was not cracked, for $30. I checked it out when I bought it, and saw no cracks. When I went to put it on, I looked again and saw a super thin hairline crack. Anyway, no one died, so I get to do this writeup.

I sanded the area with some fine sand paper, and wiped it down with lacquer thinner and let it dry.

 

The next step is to mix the Quiksteel and apply it. You don’t want to dilly dally, because this stuff will start to harden pretty fast. Mix it until it is like a frosting consistancy, only 20 seconds or so.

I then applied it with a small flat screwdriver. It is about 3/16-1/4 thick at the crack line. As it started hardening, I wet my finger and went back and tapered it down on the edges.

 

The instructions say to let it set up for 3-4 hours. It is 76 degrees outside right now, so I am going to set it outside on my balcony.

 

I did around the base of both of them.

 

I waited 30 minutes, after it was firm to the touch, then applied another layer onto of where the crack is. This is not in the instructions, so we will see if it turns out ok.

 

The final step says to cure with a heat source at 250 degrees but doesn’t say how long. Maybe they mean 15 minutes like the curing on the vehicle precedure? I let it cure at 250 degrees for 1 hour. I will turn off the oven and leave it in there over night.

 

I went off the grid from the instructions a bit.
I will post my results if it fails.

 

Wife don’t like gun kote or smelly headers cured in the oven but mom ok with it as long as grand kids come over too


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Ok, so I waited about 22 hours. And then I started it and let it idle for 15 minutes before turning it off and letting it cool down.

I have done all 3 cure procedures....

We will see.

 

I hope this works out for you Jon. Id be interested to see your results.
Over the years I’ve made many an attempt with no success (pre-heating, capping it & filling it with gas, beveled the crack, mig, tig, stick, etc etc.).

 

I watched many Youtube reviews with little success. I used it several years ago and it bubbled up, I redid it and it worked.

 

Not to pee in ur wheaties but for the labor involved I'd buy a new manifold... you can get one for under $100 to your door

 

You should have offered yesterday, and I would have given you my address!:happyyes:

 

Lol.... prolly give your address to 1a auto when you paypal them.....

Hopefully this will work well enough to satisfy you.

 

Easy killer... the only reason I mentioned is was in case you didn't know a stock replacement could be had that cheap and might want to change your plan before you did the work to put it back on.....

You aren't the first person to try to repair the stock manifold..... lots of folks have welded, brazed, puttied, wrapped, etc...... Absolutely nothing wrong with doing a writeup

I'm certainly not trying to discourage you from doing your own thing....

 

This is a common problem with Jeep exhaust manifolds for some reason or another. I had the same problem so I bought a stainless steel header and haven’t had a problem since. Not sure if the metal the Jeep manufacture uses is shitty or what.

 

Yeah Jeeps aren’t the only manifolds that crack like that. Many classic vehicles suffer from this problem. (Probably has to do with the constant heat/cooll cycles?)
Some people claim to be able to braze them. From what I understand? I guess the manifold has to be damn near surgically clean (which makes sense if you’ve ever tried to re-solder old pipe.) Which takes a Lot of work by itself.

 

The problem with brazing or welding is that the manifold just cracks again next to the repair....

The op's putty fix MAY actually have an advantage if one side breaks free from the putty and floats in the hole it left staying mostly sealed....

 

UPDATE: FAILURE

The material cracked and fell off exposing the original crack. I hate to go Dorman, but I guess I will.

 

Sorry it failed on ya but don't let dorman worry you....they a really well made.... much better than oem....
I don't ever use the gasket that comes w em tho... I get a felpro locally.

 

I am looking at the Banks 51327 Torque Tube System, it is $400 and the Dorman is $200, basically.

My thoughts
Mandrel bends vs compression bends, everyone agrees that mandrel is the way to go, right? Well those little crinkle things in the dorman HAS to be worse for the exhaust signal than compression bends.

I know the 4.0 isn’t a power beast, which is exactly why I think I should maintain every advantage that I can.

I would hate to spend the $200 and regret it.

 

I am looking at the Banks 51327 Torque Tube System, it is $400 and the Dorman is $200, basically.

My thoughts
Mandrel bends vs compression bends, everyone agrees that mandrel is the way to go, right? Well those little crinkle things in the dorman HAS to be worse for the exhaust signal than compression bends.

I know the 4.0 isn’t a power beast, which is exactly why I think I should maintain every advantage that I can.

I would hate to spend the $200 and regret it.

Those "those little crinkle things" are flex joints. Jeep added them in around 1997ish after all the problems they had with the early manifolds cracking. They are a good thing because they allow some flex when they heat and cool.

Stainless headers also crack, stainless seems to be a bad choice when it comes to 4.0 headers. Many years ago there was a poll taken on cracked headers and manifolds and Doug Thorley header did not have any reported failures. They were the heaviest built thickest wall tube headers you could buy and they were not stainless. They were chromed and do eventually rust but they were built like a brick s#*!house.

Mine has been on my jeep for around 15 years and hasn't cracked yet. The bad news is Doug Thorley no longer makes them they went to using stainless.

If i needed to replace my manifold today i would get a dorman and skip anything made from stainless. I noticed no power gains from my Doug Thorley anyways.

 

What is the part number on the dorman you're looking at?

My dorman is all mandrel bent

 

Dorman 674-196

Is what pops up on Amazon.
They are mandrel bent, based on the picture.

But the turbulence caused by the “flex joints”, I don’t know.

 

Also i dont think dorman makes anything they just sell stuff under their brand and mark the price up. If you look on ebay you can find the dorman type manifolds for a fraction of the price. I am sure they all come out of the same factory in china.


https://www.ebay.com/itm/Steel-Exha...L/182498426390?fits=Make:Jeep&hash=item2a7dc0fe16:g:NmoAAOSwuxFYtrkI:rk:13:pf:0

 

You shoulda gone w the dorman or even the $54 one.....

You won't get anything more at all for your $400 except a banks sticker....

The turbulence you are concerned about is an imagined problem....

 

You won't get anything more at all for your $400 except a banks sticker....

Well if this one cracks, he can put the sticker over the crack!

 

2 stickers, I think. And it is all relative, we all spend a bit where others wouldn’t and save where others would spend. Turbulences, backpressures and cats are a bit more of a reality to californians trying to get through smog tests every year, lol. Any gains or avoidances are welcomed.

 

Well either way...... best of luck to ya n happy jeeping.

 

It you don’t get the accordion joints it will crack but if you want to spend more and break sooner it is your time and money


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