Exhaust Pipe question

Post by **Ryan_Miller** » Tue Aug 29, 2006 9:42 pm

I have been working on my exhaust system and have a couple of questions to verify.

1. Looking through the ORD 9 parts list, I do not see any rubber pads listed for the pipe mount brakets to the frame. Is this correct.

2. when connecting my pipes I have had to apply some pressure to get the pipes to line upand connect together when mounting them to the frame.
I have a NOS header pipe (U shape that connects to the exhaust manifold) and a NOS muffler. The center pipe section is a repro.
I am thinking the repro may be off a bit. I could still get everything mounted, but I am wondering how much pressure is acceptable since there are no rubber connectors (if I am reading the ORD 9 correctly).

I am worried about the pressure being a problem cracking stuff with the engine torque when I finally get her running.

Should the pipes fit loosely and exactly?

The middle pipe comes close to the tranny cross member too.

davem201m38 · Post by **davem201m38** » Wed Aug 30, 2006 2:11 am

Hi Ryan,
I can confirm it is a pig to fit. Yes I had to put some gentle EFFORT into slightly bending pipes. Lots of effort but only very minor adjustments needed. I think this is probably due to lax spring-back tollerances being used when the pipe is bent.

I still have a full original un-rusted through exhaust system in my garage, luckily my jeep stood many years in a very dry arid climate, the replacement I bought from the states looked identical when laid on the ground.

So...... I tried using the original down pipe and long pipe but with the replacement silencer, didn't fit nice.

Eventually I found out that I couldn't mix the two systems, it was one or the other but not parts of both. I guess it starts and ends up at the same place but how it gets there is slightly different for both systems.

The centre mounting; WOW didn't even know it existed till I saw your photo!!!. I made one but with a rubber belt strip and fitted it exactly where (I now know) it should have been all the time. The rear hanger; I used a standard exhaust hanger I bought for tuppence from the cars parts shop.

I (wrongly) assumed the hangers would be flexible or have rubber to absorb vibration so I re-did them that way. Thinking back now I can't remember what held the exhaust in place, baler wire I think.
I also added another flexy hanger dropping it from the rear tub x-member someplace, I will have to go and look.

My last flange at the rear does not form a perpendicular face to mate to a extended fording pipe but I'll cross that bridge if and when I ever buy a fording pipe!!, the original system did form a good vertical mating flange.
I have not seen a replacement exhaust with a vertical flange (they are usually off by 20/30 degrees) on the exit to the silencer so I assume it's a common problem, but then I don't get to see too many M38s and I may be referring to as few as two others with that staement!!

Luckily the system doesn't jam/bang/rattle or clatter along any of the route. But it is a pig.
All the best,
Dave.

Cacti_Ken · Post by **Cacti_Ken** » Wed Aug 30, 2006 2:23 pm

Ryan, Having to put a little pressure in getting the hangers to line up to the frame is probably normal.
About things cracking when engine torques. The torque in mine wasn't hardly noticable. And when metal gets hot it will give some to the pressure. So I don't think you have any thing to worry about.
My middle hanger had rubber cushion under the frame when I first removed it. So I put a piece back.
At least you got by without having to torch heat the pipes to get yours to fit. I had to do some bending on my long pipe on both bends before the muffler.
And the pipe should clear the crossmember without touching any other objects. If it does it will rattle.

Looking good.

Ken

OKCM38CDN · Post by **OKCM38CDN** » Wed Aug 30, 2006 3:16 pm

Ryan,

Your installation is correct per the SNL... On my repro long pipe I had to heat it up a little to get it to fit at the muffler... JBizal told me this was due to an error in manufacturing, it has since been corrected...

Your installation looks just like mine... Just remember to use "BRASS" nuts on all your bolts from the manifold back

only bolts not getting brass are the ones on the mounting brackets...

Hope this helps...

Post by **Ryan_Miller** » Wed Aug 30, 2006 6:10 pm

Thanks guys!

I will probably have to heat/bend mine a little as the middle pipe seems to be touching the tranny cross member ( you really can't tell in the photo).

Hal, you are right, I forgot that the nuts for the bolts connecting the pipes are brass self locking! 5/16-24NF-3 quantity 6 (critical installment)
I need to get some of those, the devil is in the details.

I sometimes get frustrated with the repro stuff. I am do it right or don't do it type of person, so I don't understand why they make reproduction stuff that does not fit.

As you can see, I have been making some progress (slowly).

The tub is painted and I have put on some brackets, I just need to get all the running gear together before I put it on.

OKCM38CDN · Post by **OKCM38CDN** » Wed Aug 30, 2006 8:22 pm

Ryan,

Wes can correct me if I am wrong, but your installation looks fine. The pipe does fit close to the tranny crossmember. I can not tell if the last bracket under the rear cross member is correct but it should almost but against the cross member...

I posted photos of mine a while back...

Hope this helps...

DougK · Post by **DougK** » Thu Aug 31, 2006 12:49 pm

Ryan:

I purchased my pipe and muffler from AJP George Baxter at the Alameda Convention in 2003. He told me at the time he had one kind from the manufacturer that came with the wrong bend in it. He guaranteed me it could be bent correctly with the proper equipment. I purchased it (for a very good price reduction) and had a local shop install it. I still made out financially.

He was very up front about the problem but had new ones on order.

Post by **Ryan_Miller** » Fri Sep 01, 2006 9:41 am

That middle pipe is touching the tranny crossmember engine stay cable bracket. I think I can make some minor adjustments, when I first put it together it was about 1/4 inch above the bracket. Then I had to make some other adjustments so I loosend the brackets and pipe connecting bolts. I retightened them from the back to the front, I did not pay attention to that area.

I think if I loosen things back up and watch what I am doing a little close, I should be able to get it right.

Hal, you don't happen to know of a place to get brass flex lock nuts do you?
I started calling around and it seems to be one of those harder to find items.

Cacti_Ken · Post by **Cacti_Ken** » Fri Sep 01, 2006 3:38 pm

Did you use 3/8" bolts on your flanges?
I used 5/16" bolts, but I couldn't find any 5/16" fine thread nuts. So I had to use steel and put high temp. Never Seeze on the threads.

OKCM38CDN · Post by **OKCM38CDN** » Fri Sep 01, 2006 4:00 pm

Ryan & Ken,

I just bought plain 3/8x24 bolts and added plain brass nuts... The SNL calls for the same type of nuts used on the manifold... Brent Mullins has them about $3. each...

Let me check a place here in the city (Fastener supply house) in the morning to see what they might have...

Hope this helps...

Post by **Ryan_Miller** » Sat Sep 02, 2006 10:52 am

Hey guys,

I just found this place on the internet and it is a few miles from my house.

They have every type of lock nut in every type of metal per the web page.

I'll have to check it out next week.

http://www.locknuts.com/xx-loc.html

petesilfven · Post by **petesilfven** » Wed Sep 06, 2006 4:42 pm

In a practical way, it isn't really important to use brass nuts except on studs. If a nut/bolt assembly seizes up, just twist it off and use new hardware, which would be the correct thing to do anyway.

BTW, the hard exhaust hangers may be correct, but if you are going to drive the jeep to any extent, you'll soon put rubber hangers on. The noise is unbelievable.

OKCM38CDN · Post by **OKCM38CDN** » Wed Sep 06, 2006 8:34 pm

I am running the original hangers and do not get any noise from my exhaust other thatn the motor noise... I made sure it was good and tight...

Hope this helps...

maeserik · Post by **maeserik** » Fri Nov 17, 2006 3:48 am

i replaced my bubba exhaust by an original, fits perfectly and there are no rubber hangers, jeep sounds nice.
i know the muffler ends not perfectly horizontal, i will would not make tension on the exhaustmanifold.

Erik

Post by **Ryan_Miller** » Sat Nov 18, 2006 9:23 am

Erik,

Your exhaust system looks good!

I have talked to several "old timers" and they have told me that the exhausts usually need a little adjustment to get the tip to be straight as it comes out by the rear bumper.

Mine is very close and I don't plan on using the fording kit.