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Discussion Starter #1
I am trying to remove the catback from the headers. The passenger side came off with a little coaxing but the driver side is locked on. The bolts were rusty but they are all out. I removed the coupling to the crossover pipe also.

The pipe closest to the trans seems to be the issue. I have PB blasted and heated it and I have hit it with PB blaster again. I have hit the flange with a hammer but it just isn't budging.

If anyone has run into this before and have any recommendations they would be greatly appreciated.

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There is a ring gasket on the inner pipes on each side, could try to liberally spray with something like WD40 or equivalent in between both flanges a few times and try to twist it off, or pry between the flanges with a long screw driver? You'd likely need to replace the gasket afterwards.
 

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I had a hell of a time getting the exhaust off the first time when diagnosing a drive line issue. Actually was unsuccessful, but the Indy I took the car to was able to get it down when they replaced the diff. I think it helps to have a lift and/or more than one set of hands. If I remember, one of the tubes on each side is a slip fit and the other has the ring gasket and the slip fit is the problem. I think it is a matter of pulling back at the right angle.
 

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I have had a few stuck and gzig's description is accurate in my books. You need to support the end of the pipes and have then in there natural position then use a special tool for separating the pieces. My tool is not handy and I searched the net for a pic but could not find one but found something close which will give you an idea. I used disassembly wedges one on each side of the pipe between the flanges. Cold chisel likely has to steep a angle on it's tip but might work. Something like this would be better.
images.duckduckgo.com.jpg
The actual tool I used in the past is for splitting the join of engine and transmission on farm tractors or alike. They are more tapered than what is in the picture. The more tapered equals more spreading force per blow but tractors are much heavier than your exhaust so likely any steel wedge will do the job. Just do each side even to the pipe stays straight. Likely available at any auto parts store.
 

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Discussion Starter #5
The pipe that is stuck has the floating flange so there is nothing to wedge against. The other side has 2 fixed flanges but it is loose. Unfortunately wedges won't work on this junction.

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How about a exhaust pipe clamp on the back side of the floating flange. The cat(no pun intended) must be skinned, a lot of these things take creativity.
 

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Discussion Starter #7
How about a exhaust pipe clamp on the back side of the floating flange. The cat(no pun intended) must be skinned, a lot of these things take creativity.
I thought about doing that. I just need to wait for my clamps to arrive.

Believe me I haven't given up. I am Mr outside the box when it comes to things like this.

Figured I would put it out there and see if anyone has seen this before I went rogue.

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This is easier to remove that you think...ran into the same issue. All you need is a little counter weight. Remove the entire exhaust system from the back forward and the weight will pull it off cleanly as you slowly drop the exhaust from the back. Good luck!
 

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After slide hammers, MAPP torch and every form of penetrating fluid failed, I finally split the joints on my headers using M8 nuts and bolts to force the flanges apart. The loose flanges stop against a shoulder in the pipe. This was a RHD car but I would think the pipes are similar to LHD and all have the shoulder in the pipe to make this possible? It took a long time but this method puts a lot of force (tonnes) on the joint without putting stress on other areas. The pipe fits inside the outer part by about 3/4 of an inch (20mm) and were seized solid. There is some risk of the flange cracking but since they were so badly seized I figured there was no other way of getting them apart other than cutting them off.


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Discussion Starter #12
After slide hammers, MAPP torch and every form of penetrating fluid failed, I finally split the joints on my headers using M8 nuts and bolts to force the flanges apart. The loose flanges stop against a shoulder in the pipe. This was a RHD car but I would think the pipes are similar to LHD and all have the shoulder in the pipe to make this possible? It took a long time but this method puts a lot of force (tonnes) on the joint without putting stress on other areas. The pipe fits inside the outer part by about 3/4 of an inch (20mm) and were seized solid. There is some risk of the flange cracking but since they were so badly seized I figured there was no other way of getting them apart other than cutting them off.


View attachment 817745
I like it and will try it. That is definitely outside the box there. Thanks for posting.

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I think those were actually M10 fasteners, I had 40mm and 50mm long ones to hand. A pair of washers in front of each nut can help keep the friction lower as you wind the nuts outwards, plus a bit of oil. I hope it works for you too.
 

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Discussion Starter #14
I think those were actually M10 fasteners, I had 40mm and 50mm long ones to hand. A pair of washers in front of each nut can help keep the friction lower as you wind the nuts outwards, plus a bit of oil. I hope it works for you too.
It worked. I used M8 fasteners. Half the donut came off in the catback but it is off.

THE39M5 I owe you a beer. Let me know where to take it. When that thing started moving I was happier than a pig in slop.

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After slide hammers, MAPP torch and every form of penetrating fluid failed, I finally split the joints on my headers using M8 nuts and bolts to force the flanges apart. The loose flanges stop against a shoulder in the pipe. This was a RHD car but I would think the pipes are similar to LHD and all have the shoulder in the pipe to make this possible? It took a long time but this method puts a lot of force (tonnes) on the joint without putting stress on other areas. The pipe fits inside the outer part by about 3/4 of an inch (20mm) and were seized solid. There is some risk of the flange cracking but since they were so badly seized I figured there was no other way of getting them apart other than cutting them off.


View attachment 817745
This is genies. Been soaking my exhaust in PB buster for days and pry bar and not budging. This method worked like a dream. Popped each side in minutes. Thank you
 
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