Exhaust manifold removal tips

Stock FSJ Tech Area
Post Reply
User avatar

Topic author
kjandb
Posts: 97
Joined: Mon Oct 25, 2021 11:58 am

Exhaust manifold removal tips

Post by kjandb »

I have a good leak from the bottom of the manifold so I'm going to attempt to replace the gasket. Never done anything like this before so please share any suggestions. I have the remflex gasket and plan on using high tack sealant to hold it in place.

Will I have to remove anything else or will they drop out the bottom? Everything appears to be stock - 1971 360.

I was able to loosen all drivers side bolts with a little convincing. Let's hope passenger side is the same.

This will be a good opportunity to cleanup the temporary fix for those injection tubes too.ImageImage

Sent from my SM-G991U using Tapatalk

'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
S Idaho
User avatar

Topic author
kjandb
Posts: 97
Joined: Mon Oct 25, 2021 11:58 am

Re: Exhaust manifold removal tips

Post by kjandb »

Removed both manifolds without issues. Is it normal to not have any gasket at all? Metal on metal.

Manifold bolts came right out but I didn't have the same luck with the banjo bolts. Gonna pb blast them daily and see if the other 7 turn out better.

ImageImageImage
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
S Idaho
User avatar

Stuka
Site Admin
Posts: 11789
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: Exhaust manifold removal tips

Post by Stuka »

The banjo bolts are a major PITA. They get brittle from the heat cycles, and they are hollow. A recipe for breaking. I had to use an easy out last time I had to remove some. And I had to hammer it in to get it to grab.

And as I recall there was no gasket from the factory. The gasket you have is good. But don't put high tack on it. Its not rated for that kind of heat. You really should not need to use a sealant with that gasket. But if you wanted that extra bit of sealing power, you should use a spray on copper coat.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

deckside
Posts: 40
Joined: Thu Aug 13, 2015 1:16 pm

Re: Exhaust manifold removal tips

Post by deckside »

Getting the manifolds back on is a pain in the ass. Suggest using two studs each side for help getting them back in place. Remflex should be fine

letank
Posts: 4009
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: Exhaust manifold removal tips

Post by letank »

real PITA, I try to use the remflex, but it was too cumbersome because of their thickness and instead use the copper gasket from Mr gasket MRG7174. that was over 15 years ago... still holding.

as for the air tube, heat and more heat, aka the blue torch. I think most people brake the easy out.

Some shops specialize in removing these, I forgot the name of the procedure, searching: it is called induction heater ...
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
User avatar

1978J10REDWHITE
Posts: 263
Joined: Fri Nov 20, 2020 7:25 pm

Re: Exhaust manifold removal tips

Post by 1978J10REDWHITE »

I removed the, and used the blue tip and had to really "cook them" to make the metals removable workable, and PB Blaster. Make sure you run a thread tap in head bolts holes and flush out holes and anti-seize on blots to remount. There is no easy way but quit doable
Enjoy.

sierrablue
Posts: 1208
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Exhaust manifold removal tips

Post by sierrablue »

I HIGHLY recommend the copper gaskets if you can get them/haven't put it back on yet.

The copper ones you can tighten down again when they start leaking, and it will go quiet again, so you don't have to take
them off/replace them all of the time.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

OldFarmTruck22
Posts: 244
Joined: Sat Mar 05, 2022 4:35 pm

Re: Exhaust manifold removal tips

Post by OldFarmTruck22 »

After you remove those tube bolts and the inner tubes, what do you put back in to seal those holes? I'd like to get rid of those internal tubes.
78 FSJ AMC 360 Quadratrac
User avatar

Topic author
kjandb
Posts: 97
Joined: Mon Oct 25, 2021 11:58 am

Re: Exhaust manifold removal tips

Post by kjandb »

BJ's makes a kit (I'm sure others to do) but for some reason there is only 7 bolts in their kit? I need 8.
https://www.bjsoffroad.com/AMC-V8-Exhau ... _2000.html

I'll probably find something locally. They're 9/16 but would have to be pretty short. Might need to cut them down to size?
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
S Idaho

OldFarmTruck22
Posts: 244
Joined: Sat Mar 05, 2022 4:35 pm

Re: Exhaust manifold removal tips

Post by OldFarmTruck22 »

Do you put pipe plugs back in?
78 FSJ AMC 360 Quadratrac
User avatar

Stuka
Site Admin
Posts: 11789
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: Exhaust manifold removal tips

Post by Stuka »

kjandb wrote: Wed Jan 25, 2023 9:03 am BJ's makes a kit (I'm sure others to do) but for some reason there is only 7 bolts in their kit? I need 8.
https://www.bjsoffroad.com/AMC-V8-Exhau ... _2000.html

I'll probably find something locally. They're 9/16 but would have to be pretty short. Might need to cut them down to size?
Later exhaust manifolds only have seven injection tubes. So their fitment years are a bit off.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
User avatar

Topic author
kjandb
Posts: 97
Joined: Mon Oct 25, 2021 11:58 am

Re: Exhaust manifold removal tips

Post by kjandb »

Can I ask a few more noob questions?

1) I can't find any decent 3/8 bolts locally so I might just order from McMaster - I'm assuming the zinc-flake-coated will work?
https://www.mcmaster.com/screws/high-st ... ze~3-8-16/

2) Is there a reason to keep the entire gasket intact or should I cut it up into 3 sections to match the exhaust holes? I just noticed it bumps into the valve cover in a few spots and might be easier to cut up.


Image
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
S Idaho

OldFarmTruck22
Posts: 244
Joined: Sat Mar 05, 2022 4:35 pm

Re: Exhaust manifold removal tips

Post by OldFarmTruck22 »

kjandb wrote: Fri Jan 27, 2023 6:58 am Can I ask a few more noob questions?

1) I can't find any decent 3/8 bolts locally so I might just order from McMaster - I'm assuming the zinc-flake-coated will work?
https://www.mcmaster.com/screws/high-st ... ze~3-8-16/

2) Is there a reason to keep the entire gasket intact or should I cut it up into 3 sections to match the exhaust holes? I just noticed it bumps into the valve cover in a few spots and might be easier to cut up.


Image
My manifold gaskets came in the box in 3 pieces for each side. I'd trim that excess from along the top so it doesn't touch the valve cover too.
78 FSJ AMC 360 Quadratrac
User avatar

Stuka
Site Admin
Posts: 11789
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: Exhaust manifold removal tips

Post by Stuka »

kjandb wrote: Fri Jan 27, 2023 6:58 am Can I ask a few more noob questions?

1) I can't find any decent 3/8 bolts locally so I might just order from McMaster - I'm assuming the zinc-flake-coated will work?
https://www.mcmaster.com/screws/high-st ... ze~3-8-16/

2) Is there a reason to keep the entire gasket intact or should I cut it up into 3 sections to match the exhaust holes? I just noticed it bumps into the valve cover in a few spots and might be easier to cut up.
Its a lot easier to install as one piece. You can trim it down so it doesn't hit the valve cover.

Did you verify your heads only have 3/8" bolts? Some heads have two 3/8", and four 5/16".
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ
User avatar

Topic author
kjandb
Posts: 97
Joined: Mon Oct 25, 2021 11:58 am

Re: Exhaust manifold removal tips

Post by kjandb »

Yes, all are 3/8-16 1.5". And now that I look at McMasters I'll have to go yellow-chromate to get the fully threaded.

A few weird observations though - all 4 edge bolts had a much thicker washer. And the bolt holes in the manifold seem to be very large - much larger than what's needed for 3/8". There's a lot of play. I'm sure there was a reason for that?
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
S Idaho
User avatar

Yeller
Posts: 1521
Joined: Thu Apr 01, 2021 7:54 am
Location: Rogers County Oklahoma

Re: Exhaust manifold removal tips

Post by Yeller »

The large holes allow the manifold to move from heat expansion and not break the bolts over time
The bus I ride is so short it is a yellow Smart Car full of squirrels, monkeys and clowns.

1970 J2500 Resto Mod
https://www.fsjnetwork.com/forum/viewt ... 12&t=21395

1974 Bronco “Broncno”
https://classicbroncos.com/forums/threa ... st-3411909
User avatar

tgreese
Posts: 7117
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Exhaust manifold removal tips

Post by tgreese »

Stuka wrote: Mon Jan 23, 2023 2:12 pm And as I recall there was no gasket from the factory. ...
Yep.

JMO - don't use a conventional gasket. It will need replacement in a few years. If the manifold and head surface is clean and not eroded by exhaust gas, put it back like the factory had it with no gasket. You can have the manifolds surface ground if their sealing surface is no longer flat. If I insisted on a gasket, I would use Remflex gaskets. Or copper, as mentioned above.

Note the gaskets at the pipes have also been superceded by an iron/steel gasket, either a steel ring or the shape of the gasket as part of manifold. This lasts better than the composition doughnut or flat gasket.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Exhaust manifold removal tips

Post by candymancan »

Question. Why do the amc360 need gaskets but the 369 magnun dont ? My 5.9 in ny grand cherokee they dont come with gaskets.. yoire suppose to bolt it on withkut one as well.. as the gasket causes leaks.

So i wonder is this why the exhaust is leaking on the amcs because of the gaskets ?
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
User avatar

tgreese
Posts: 7117
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Exhaust manifold removal tips

Post by tgreese »

Does not need gaskets. It's a modernity thing. The '70s 360s that I remember in the '70s were metal on metal at the cylinder head. The pipe gaskets were composition, and they changed in that decade to metal on metal. When I sold parts ca 1980, Felpro had a replacement doughnut gasket of iron. The manifolds were changed to include the doughnut shape in that era too ... even that iron doughnut went away eventually.

You can look at the parts book and see this. The cylinder head exhaust gaskets are an aftermarket thing. If you find gaskets, it's some later owner that has improved the factory condition with aftermarket gaskets. Possible that there were gaskets on the earlier V8s - you could look at the '62-73 parts book and maybe get some hints there.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

sierrablue
Posts: 1208
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Exhaust manifold removal tips

Post by sierrablue »

The earlier ones didn't have gaskets. I guarantee it, except maybe on the I-6s
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
Post Reply