Exhaust geometry problems

[TRevs]

Shortly after i acquired the YJ, I discovered a cracked exhaust manifold and decided to replace the whole exhaust. I had never done anything like this; I went ahead and bought a complete kit from RockAuto (cheapest Walker option) and bolted it all together.

I was moderately pleased with myself and it seemed fine. The pipe goes pretty low under the oil pan, reducing my ground clearance:

but I noticed recently that the hanger to the transmission has broken, and there’s not much weight being borne by the hanger at the rear of the muffler. So most of the weight is being carried by the manifold and tailpipe hanger (and the transmission skid plate apparently).

I’m wondering if I should take off all the U bolts and start over with the same parts, and try to weld the broken hanger on again (I just got a 110v welder and am learning). Or start over with better quality parts, or just pay a shop to fix it. I’d like to be able to get rid of the transfer case drop, which is currently lowering the transmission hanger 1” lower.

 

[machoheadgames]

Gonna watch how this one goes.

I can’t really help but I am curious how your muffler and curved part of the tailpipe sits.

I have no transfer case drop, all stock engine mounting, and my exhaust results have been pretty stupid. A full suite of Walker products has the tailpipe basically jammed into the tub. I am currently running my Magnaflow cat back because it doesn’t have the issues hitting the tub. However, it hits the tailpipe hanger, so I’m still working on a solution for that.

I haven’t had any issues with the transmission mounting point, I am assuming your issue is caused by the misalignment of brought about by the t-case drop.

 

[TRevs]

i think part if the problem is low quality materials; that hanger to the transmission mount apparently couldn’t hold the weight so now everything is sagging. I’ll have to do some research and make a plan. It would be nice to get good quality materials and workmanship that will last a long time, but those seem to be rare these days.

 

[Plastic Fury]

I pieced my exhaust together and it's worked very well for me. I have a Banks header (which doesn't matter for this conversation) with a JBA mid pipe from that header that routes the exhaust in front of the oil pan like the TJ. I did have to move the hanger back a few inches to make it sit properly and I had to clearance the piping a bit so it didn't rub the transmission. The rest is made up of Walker parts, straight section (no cat), Walker SS muffler and Walker tail pipe section. Everything is just clamped together and installed very well. With the 1" body lift / 1" motor mount lift, my transfer case is not dropped with my suspension lift so the exhaust sits where it should. I used new hangers and I have had no issues now in just over a year. No rattles, nothing touches anywhere and I am happy with the sound. I have been very pleased with how easy it all went together and how well it's holding up.

 

[TRevs]

I pieced my exhaust together and it's worked very well for me. I have a Banks header (which doesn't matter for this conversation) with a JBA mid pipe from that header that routes the exhaust in front of the oil pan like the TJ. I did have to move the hanger back a few inches to make it sit properly and I had to clearance the piping a bit so it didn't rub the transmission. The rest is made up of Walker parts, straight section (no cat), Walker SS muffler and Walker tail pipe section. Everything is just clamped together and installed very well. With the 1" body lift / 1" motor mount lift, my transfer case is not dropped with my suspension lift so the exhaust sits where it should. I used new hangers and I have had no issues now in just over a year. No rattles, nothing touches anywhere and I am happy with the sound. I have been very pleased with how easy it all went together and how well it's holding up.

That looks great! I think I could pull off something like that. Looks like you used better clamps than I did. Also, is the mid pipe hanger curved to go into the rubber slot in the skid mount? Mine is flat stock and obviously didn’t fit well.

My other confusion is how to test fit everything: is it just repeated trial and error to get things lined up? Is there a method, like start at the front and work backwards? Did you cut off and re-weld hangers when you had to move them? How did you “clearance “ the pipe? Just a big hammer?

 

[Plastic Fury]

It really was very easy to do overall. I don't have a welder so I wanted to get it together and not have to take it to a shop. I decided to give those clamps a shot and thus far, they have worked very well. The mid pipe hanger is curved and fits into the rubber hanger just as if it was OEM. That JBA mid pipe is not a cheap part and it's made VERY well, so that is not surprising.

For fitment, I started with the header, then fit the mid-pipe and worked my way back. I held up the mid-pipe with a jackstand and after messing with it a few times by rotating the pipe, etc for good fitment at the header and tucked up around the pan, I found the sweet spot for it. Unfortunately, that required the hanger to be moved a few inches as where it came, it was jammed into the mount and I needed a bit more room. I took it to a buddy and he welded it for me. After that, it fit well but was just touching the transmission, so I clearanced it with a small sledge hammer, which gave it plenty of room and hasn't been an issue. I wasn't planning to run a cat so I bought a straight section of Walker pipe to go from the mid pipe to the muffler. I didn't have to cut it as the mid pipe slide right into it and gave me several inches of adjustment by just simply sliding it to where I needed it to be. It then slid right into the Walker SS muffler. The trickiest part was the tail pipe section that curves immediately after the muffler. (I also used exhaust tape on each joint and then clamped over that)

I basically bolted the mid pipe to the header and then the rest of it was loosely fit until I had it all where I wanted it. The mid pipe sits firm in the hanger and the tail pipe sits well in the hangers back there as well. The header and mid pipe were pricey but the rest was not.

You can see in the pic how far I needed to move the hanger.

 

[TRevs]

Thanks for the extra info. I looked a couple places and that midpipe is around $390 and out of stock. But I may go that route eventually so I don’t have to keep messing with rusting broken parts every year or two.

Did you remove the skid plate for better access?

 

[Plastic Fury]

Thanks for the extra info. I looked a couple places and that midpipe is around $390 and out of stock. But I may go that route eventually so I don’t have to keep messing with rusting broken parts every year or two.

Did you remove the skid plate for better access?

Yeah, I kept looking at it for a while because it was pricy. I think when I bought it, it was about $350. I finally said screw it and pulled the trigger. It looked well made and it is so I had the same thought, that it would probably outlast the Jeep lol.

Nope, I installed it all with the skid plate in place, it was no problem at all.