AMC Eagle Den Forum

The Mighty 258 => Exhaust System. => Topic started by: flamingchariots on June 24, 2011, 10:23:04 PM

Title: Front pipe flange nuts
Post by: flamingchariots on June 24, 2011, 10:23:04 PM
I've been working on my 6 cyl. '84 wagon, replacing the exhaust system. 
I'm having difficulty figuring out how to access the flange nuts on the manifold end of the front pipe. 

I can see them from below, and see the small access hole right by the engine mount.  The problem is that I can't get a socket on either of the nuts straight.  I've tried a wobbly universal adapter, but don't feel comfortable trying to wrench on it from an angle.

I've been spraying the nuts with PB blaster for several days now. 
Living in the rust belt, I've busted off way too many bolts/studs...
Is there something I'm missing?  Special tools? 
Title: Re: Front pipe flange nuts
Post by: thereverendbill on June 26, 2011, 10:24:05 AM
What I used to get mine off was one of those specialty sockets with the ball style universal joint.  Everytime I tried to do it with a socket and a universal joint the dang thing would bind.  Harbor freight sells the whole kit for right under 20 dollars
Title: Re: Front pipe flange nuts
Post by: flamingchariots on June 26, 2011, 02:30:02 PM
Thanks for the tip.  I wasn't sure I would get a reply!
I've spent some time searching for the tool you mentioned online, but I can't seem to locate anything under that description.
Would you have a part number or link to where I could see a picture of what it looks like?

I appreciate the information.

Yesterday I removed the canister filter (Is that right? Looks like a 1 lb. coffee can with hoses) and mount to gain more access from the engine compartment side, with not much success.  I was able to get a short 9/16" socket and ratchet on one nut, but I had no leverage to break it free. 
Title: Re: Front pipe flange nuts
Post by: thereverendbill on June 26, 2011, 02:35:21 PM
67929 is the part number from harbor freight
Title: Re: Front pipe flange nuts
Post by: BenM on June 27, 2011, 09:48:56 PM
I got really lucky and inherited a set of Snap-On sockets with the universal joint in the socket itself, and the one time it needed to work, it did. The other 5 or 6 times, I've succeded in snapping the studs on the exhaust manifold.

When you get it off I'd make sure to runt a die over the studs; drilling them out is no fun and if I had to do that again I'd find someone with a drill press.
Title: Re: Front pipe flange nuts
Post by: KyleB. on June 28, 2011, 06:59:59 PM
here's the trick:
take a 9/16 socket, not a deepwell, & weld a handle near the bottom edge.  be sure not to cover the square on the bottom of the socket.  this will allow the stud to pass through the socket as you tighten the nut.  works/fits perfefect!
Title: Re: Front pipe flange nuts
Post by: flamingchariots on June 29, 2011, 03:13:06 PM
So Ben, if you snap off the stud, the manifold needs to be pulled?  I'm half tempted to sawsall the pipe and pull the whole thing from the engine side.

I took reverendbill's info and bought the HF 67929 socket set.  I was successful at making the upper nut creak and turn a little (slowly and carefully).  I'm now soaking it with more PB blaster.  These sockets are not able to fit through the access hole in the frame by the engine mount.  I also got a set of wobble extensions (67065).  This allowed access through the hole, but no luck in freeing up the nut.  More soaking and waiting...

Thanks for the comments and hints!
Title: Re: Front pipe flange nuts
Post by: mudkicker715 on June 29, 2011, 04:11:22 PM
Just for the record. I never had a problem with a ujoint and a mile of extension for both bolts.

Also using heat helps. Like running the motor to heat it up.
Title: Re: Front pipe flange nuts
Post by: mudkicker715 on June 29, 2011, 04:16:33 PM
Forgot to mention.   From back of the tire.

Also just remembered. Iused a 3/8 rachet normal socket on the front one
Title: Re: Front pipe flange nuts
Post by: carguy87 on June 30, 2011, 11:09:45 AM
Agreed, heat helps tons, but make sure that once you get it moving, you should work it back and forth by tightening and loosening it, this will help clean those threads and keep the rust from binding and snapping that stud.  And to answer your question, yes, once they are broken, you have to remove your exhaust manifold to drill out the studs, then tap the manifold and put new ones in.  Good Luck
Title: Re: Front pipe flange nuts
Post by: BenM on July 01, 2011, 12:58:14 PM
Yeah, if the stud snaps off, you pretty much need to pull the manifold set.

Except for getting that last back nut off of the stud, which AMC seems to have forgotten enough to make it worth noting. Getting all the brackets and such off and on takes some time, but it's straightforward as you look at it and the bolts usually come out easily. You do have to unplug a few wires and should label you vacuum lines if you're not really sure about them.

It's best to just be able to get everything off without damage, slowly and easily. Throw the old nuts out.
Title: Re: Front pipe flange nuts
Post by: eagleman on July 03, 2012, 10:21:14 PM
Was just wondering how this project turned out. Facing the exact same problem now. Thinking real hard about just pulling the manifold and get it over with. Been a real fustrating day. Worked on it for three hours and am no futher now then I was yesterday. If I thought the pipe would last I would just replace the cat and the rest of the exhaust but I know what would happen if I did. So might as well suck it up and do it right the first time.
Title: Re: Front pipe flange nuts
Post by: flamingchariots on February 11, 2013, 08:19:41 PM
Sorry for the very late follow-up.  I ended up taking it to a service station which had the right tools (that I didn't).   He heated up the nuts/studs cherry red and then was able to remove the rusted nuts.  I provided the pipes and he finished the job. 
It's not much fun living in the rust belt.

On a brighter note, we've been using the Eagle the past two weeks when two of our daily drivers have been out of commission.

Kevin
Medina, Ohio
Title: Re: Front pipe flange nuts
Post by: amcfool1 on August 23, 2015, 02:43:37 AM
hi, getting the header pipe on/off ANY Eagle, or for that matter, most 6 cyl, AMCs  has always been a pita. So much so that some mainline muffler shops would actually refuse to work on these cars. There is no easy access to the downpipe to manifold bolts. And there never will be! Towards the end, AMC started to use LONG nuts, to hold the flange to the manifold. This is the secret that will make  your exhaust pipe removal/installation, if not easy, at least doable. these nuts are about an inch long, so they clear the bottom of the flange, and give you a place to put your wrench. I actually watched one muffler shop actually burn a hole through the engine mount bracket, so they could access these nuts. (many years ago)  Point being, Eagles are not easy, but they will teach you things. btw Eagle front down pipe still available at NAPA, but for how much longer, get yours, now! good luck, gz
Title: Re: Front pipe flange nuts
Post by: carnuck on August 30, 2015, 12:11:18 AM
There are 2 front pipes for the 6 cyl as well. One with EGR pipe and one with O2 sensor.
Title: Re: Front pipe flange nuts
Post by: BigBird on July 08, 2018, 12:10:14 AM
Towards the end, AMC started to use LONG nuts, to hold the flange to the manifold. This is the secret that will make  your exhaust pipe removal/installation, if not easy, at least doable. these nuts are about an inch long, so they clear the bottom of the flange,

Any idea where I can get some of these and what size / thread pitch am I looking for? My Google Fu has failed me.