Welding cat to muffler at flange?

[ecgreen]

So I can't for the life of me get the muffler flange to seal tight to the cat ouptut flange on my 89 Bronco II. I have tried a variety of gaskets to no avial - it alwasy leaks out of the bottom where the two flanges meet. Can anyone thing of a reason not to just weld the two together?

 

[Curious Hound]

I can think of a reason. But the reality is, if that’s what you have to do, then that’s what you have to do. It just means that you might have to cut it apart some day.

 

[ecgreen]

my only worry is that I believe that joint is suppose to flex. If I weld it, the stress will be where the y-pipe connects to the cat. That is a strong ass flange point though. I dont know, I think too much

 

[Curious Hound]

If the joint is loose enough to flex, its loose enough to leak. If you want a place for stuff to flex, install a piece of flex pipe.

 

[BlackBII]

I replaced that connection on my Ranger with some header collector flanges. It's been working great.

Patriot Exhaust H7259 is what I used. It's for 2.5" pipe, but I was able to get some pipe reducer adapters at Autozone since the factory pipes aren't that large.

 

[19Walt93]

I like the bell flare connectors Walker makes better- no gaskets and you can swivel it around to suit you. I weld the male end of the connector to the pipe in front and the female end to the rear section but you could switch it if you want. I couldn't find a picture of the male end but the lower right piece is the female end. No more leaky gaskets.

 

[ecgreen]

I like the bell flare connectors Walker makes better- no gaskets and you can swivel it around to suit you. I weld the male end of the connector to the pipe in front and the female end to the rear section but you could switch it if you want. I couldn't find a picture of the male end but the lower right piece is the female end. No more leaky gaskets.
View attachment 39069

I think this might be the solution. I could weld the one on the bottom right to the muffler and use a donut gasket and spring bolts.

 

[Dirtman]

You dont use a donut with that setup if you use both the male and female end. Its self sealing like a compression fitting.