Exhaust Manifold to Engine block Bolts

[1Lobo]

This process never seems to stop. Just when you think you are near the end, something else comes up to bite the derrier.
Here's the problem: I am trying to use the original hollow bolts (banjo bolts?) to attach the passenger exhaust manifold to the engine exhaust ports. These bolts seemed to bolt up all right to the drivers side of the engine, but for some reason, they get really, really tight to screw into the passenger side. Is it possible these bolts expanded? It's a remanufactured engine, and the holes don't "look" tapped. I really don't want to force these bolts into this block for the fear they may break off or worse, strip the holes. What's going on here? Are there different sized bolts on the passenger side?
That would seem quite odd, but would be par for the course on this whole engine and transmission install :mad: .
Appreciate any sort of explanation on this. Thanks.

[graham]

Recently replace exhaust gaskets on both manifolds, bolts where the same on both sides. Sure its not rusty threads inside? maybe try running a thread tap in them. Might clean up any damaged threads.

[ChargerMD]

I agree with tapping the threads out. What ever you do don't force these hollow bolts, they WILL break (don't ask). Also you might coat the bolts with high temp anti-seize lubricant before install.

[reddog]

Originally posted by ChargerMD:
I agree with tapping the threads out. What ever you do don't force these hollow bolts, they WILL break (don't ask). Also you might coat the bolts with high temp anti-seize lubricant before install.You SHOULD use anti-seize on them. There is this stuff called never-sieze in a brush top can. It is the best I have found. Pays for itself a thousand times.

Kerry

[1Lobo]

So, tapping the threads out seems to be the answer, as well as applying anti-seize.

Then, here's probably a dumb question--is it possible to damage the threads as I tap them? I mean, I will be doing this slowly, so I suppose not, but I truly don't want to damage the threads. And, what size bolts are these? The head takes a 9/16 socket.

What you all say kind of makes sense--the hole on the front of the passenger side easily accepts the bolts, but the others do not. Thought it might have been the wrong size bolt, but I will try tapping the threads first--Thanks again.

[Cliff]

Tap the holes, and go to your hardware store and buy stainless steel bolts. Never had any problem mounting mine.

[kidatforty]

Take a sample bolt with you to figure the size. I don't know about stainless bolts but definitely ant-seize and lock-washers.

[JeepBountyHunter]

are u reinstalling the airtubes with them? Not sure if that matter's or not..but seems like it could?

[turtle jim]

Might also run the bolts through a die before install

[nightflyers]

I usually just replace the hardware when I take off the exhaust manifolds. I would agree with everyone else, tap them out. Tapping is not hard, just make sure you run it in straight.

[ChargerMD]

I wonder why AMC used hollow exhaust bolts? These seem weak by nature so I can't figure out why they used them. I put mine back together using them but would have felt better using solid bolts (I figured AMC knew something I didn't.

[Doug B.]

The hollow bolts gives room for whatever needs to expand between the end of the bolt and the engine block. Less stress, especially if you get water in there.

[andy d]

i dont have good luck with stainless, use light oil or pb-blaster to lube the threads when chasing them with a tap. run it in a bit and when it starts to bind back it out and oil it then run it in a bit more. taps are brittle. i would use grade 5 or grade 8 bolts. anti sieze is a good idea too.

[graham]

Originally posted by ChargerMD:
I wonder why AMC used hollow exhaust bolts? These seem weak by nature so I can't figure out why they used them. I put mine back together using them but would have felt better using solid bolts (I figured AMC knew something I didn't.Hollow bolts...ever snapperd one off in the block??? then tried to drill it so you could use an 'easy out'.....this way if they do snap off, it's a bit easy to remove the reminants.
Maybe the only bit of forward thinking Jeep have done??

[The Preacher]

Maybe you have metric on one side and standard on the other? :D (just kidding)

This was a hot topic in the tech forum a while back. The consenus then was to replace the bolts with schedule 8 bolts and definitely apply anit-seize.

The hollow tipped bolts have a tendancy to warp which "could" be the cause of your problem. Also, the bolts ARE designed to expand and contract so it is within the realm of possibility that they have expanded just enough to give you problems.

Most of mine had some warpage so I replaced them all with schedule 8. No problems here.

Good luck.