Exhaust Clearance

Hey folks,

Things are going sweet in my new (to me) Jeep. The guy I bought it off just had a new cat back Dynamax installed.

Over every bump comes the rattle/clunk from the rear. On some startups, there is a clunk sounding like the exhaist hitting the floor dead center of the Jeep.

Now I jumped under there and noticed the tailpipe is hitting / rubbing the rear leaf, and the section that goes over the axle is about a half inch from the floor of the Jeep.

The clearance is very, very tight between the leaf and the gas tank skid plate. (1/2" on either side)

My question is:

Is it kosher to fabricate a rubber "donut" of sorts to act as a buffer between the pipe and the leaf and the pipe and the floor. How hot does that pipe get?

Do they sell "lowering" rubber hangers? The very end of the tailpipe has a metal hanger supporting a metal support rod off the pipe... leading to the never ending metal on metal squeak that I remedied by slipping a rubber tube over the rod...but why the hell would they have metal on metal with a moving part?!?!

Thanks,

~Jon

my stats:

91 YJ 4.0 auto shackles giving about 1.5" lift
Reply to
Jon
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hot enough to melt a rubber donut. Concentrate on the hangers and get them aligned properly.

The rubber isolator fell out when they did the cat-back and never got put back in. They make several types. A local muffler shop will have plenty and might even have a hanger they can thow in for you. If not, the "help" section in pepboys or autozone will have the isolator.

Reply to
DougW

Take it to a muffler shop you can trust, and let them cure your headache for you. It'll be worth it not to have to screw with an exhaust rattle in your driveway, on your back. Like Doug said, they should have the correct hanger isolator in stock, and it should be pretty cheap too.

Spdloader

Reply to
Spdloader

Thanks for the heads-up fellas!

The rattle is driving me batty. I'll pull into the muffler guy and have him take a look-see this weekend.

~Jon

Reply to
Jon

It is supposed to be rubber mounted all the way back with the tailpipe coming out at the corner on a 45 degree angle to the sides and back for fume control.

I simply went and bought generic hangers to do mine when the 'muffler' shop couldn't figure out how to install a Dynomax muffler into a CJ7 because CJ's here in Canada don't need cats and their book is American.

They just couldn't figure out how to let the main pipe run perfectly 'straight', it had to have a bend and flange.

Talk about losers calling themselves 'techs' not knowing shit if the 'computer' don't tell em so.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N> Hey folks,
Reply to
Mike Romain

Hello Mike,

Well whoever installed it has the tail pipe shooting straight out the back right between the gas tank skid plate and the rear passenger side leaf spring - leading to metal on metal squeak, and the pipe banging around over what seems to be just any imperfection in the road. It does not extend beyond the bumper, but tucked neatly and tightly in there.

To be perfectly honest, I'm not too interested in dropping it off somewhere and ponying up an hourly rate for something I could just do myself. Then again, I'm not really a mechanically inclined individual.... yet.

The last thing was a stiff steering issue, and had a referred mechanic fiddle with / troubleshoot the steering shaft & gearbox, only to discover it was a bad PS pump like I originally said to him. He went ahead and replaced it seeing that "he already had it off", soaked the engine compartment with PS fluid in the process, then washed it down with Kerosene, and now the TPS is giving me problems (code #24 / check engine light).

Of course he claims it has nothing to do with what he did, or that the fact that the steering wheel isn't quite perfectly straight is "no biggie". The fact that the steering now doesn't return to center and the engine almost conks out during idle when the peddle is tapped or on highway acceleration (TPS thing) is met with the classic "it was like that when it came in" ... like I'm some sort of idiot. I really don't feel like playing slap & tickle with the guy since there's no way to prove anything at this point. Plus, when my bullshit meter starts pegging, I have no restraint or common sense - I just see red.

I'm just already tired of dealing with "mechanic$". I truly believe they will "set things in motion" whenever they get the chance, and play Mr. Nice Guy so you return to their shop.

Sorry for the diatribe, I'm just somewhat frustrated by all this nonsense.

~Jon

Reply to
Jon

The tailpipe should be coming out on a 45 between the tire and the shackle on top of the spring. You can hang it off the frame there with a universal hanger. I just bent the metal band of the hanger into a U shape and hung it over the frame tight. There was a tab bolted to the frame there at one point that was the hanger mount. I believe YJ's are the same that way as the CJ's, just on the other side.

If it is straight out the back, the exhaust will vortex there and get in through zippers or the slightest soft top crack and smell bad besides being a CO risk. Out the side will vortex under the tire and come in under the vehicle if there are any leaks.

Mike

J> Hello Mike,

Reply to
Mike Romain

I don't remember if the OP's Jeep was a CJ or YJ, but both the OEM exhaust and the Gibson I have in my '93 exit between the gas tank skid and passenger side shackle, the OEM angled downward, the Gibson straight out. It's a tight fit - when I first put the Gibson in, I broke the rearmost hanger waaaayy up on the frame. I couldn't fix it right away, so I drove around with the most god awful clanking for a while.

What you're describ> The tailpipe should be coming out on a 45 between the tire and the

Reply to
The Merg

That downward deflection is important. If that is all the YJ has, it's easy to get an add on end piece shaped right.

Mike

The Merg wrote:

Reply to
Mike Romain

My '95 went without the rearmost hanger for some time with no clanking. You may want to check if the support that attaches by the transmission (over the skid plate) is attached. If it is not, it may be letting things move around.

Reply to
nrs

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