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Discussion Starter · #1 ·
I see it posted, I get asked all the time. How do I fix my broken exhaust manifold bolts. This has become a real common problem. I find broken bolts all the time on Dodge, GM, FORD aluminum head, cast manifolds. And I have seen alot of really bad repairs on these. And in all reality this is a pretty easy repair all things considered.

Easiest jobs-gm trucks and vans 4.8-6.0. I find these to be some of the easier ones to fix.

Worst some of the dodge trucks and 04+ ford pickups with struts (not torsion bars).

The repair is pretty much the same throughout the models and makes. Only real difference is access to the bolts.


Typically they break in three ways..

1. The head pops off, leaving the end of the bolt exposed (once manifold is removed). This is the best case scenario. Typically a stud extractor or even just a pair of pliers, vice grips can remove these ones. Pretty self explanatory.



2. The bolt breaks flush with the head. These are pretty easy to. I weld a nut over the end of the bolt and remove it.

3. Bolt breaks, and is a few threads deep in the head. These are the worse. Ill focus more in depth on this repair, break #2 is basically the same repair with just two less steps.



Removing a broken bolt a few threads deep in the hole, Ill be using my 5.3 as the example with it removed from the truck. In truck repairs are the same, just harder to work around when in the truck.

I typically remove the inner fenders to gain access to the head, remove the manifold. This gives plenty of room to make the repair typically.

I start with cleaning the surface. Once clean I take a die grinder with a carbide bit to clean the bolt and I remove the exposed threads opening up the hole to make removal of the bolt easier as it doesn't have to fight with the dirty exposed threads.



Here is the threads and the bolt cleaned up.


Next, I weld a "booger" onto the exposed piece of bolt. I allow this to cool before proceeding.


Then, I take a nut, usually will hold it in place with a pair of vise grips over the weld booger I just made. I proceed to weld into the hole of the nut making contact with the booger. Again I find it important in this step to let it cool.


Once cooled down, I slowly work the nut with a socket and rachet back and forth. Sometimes the booger will bite into the aluminum and gently working it back and forth will massage the area and allow the bolt to begin to unthread from the hole. Sometimes the welds will fail and will take a few attempts to get just the right amount of penetration with the welds.


Here's the removed broken bolt with the welded nut attached.


And here is the hole in the head once removed. Simply just run a tap in the hole to clean it up and your done.


My motor had one bolt on either head. both were the rearward most bolts. Typically its the end bolts that snap on most applications. Be careful to check if the manifold is warped as well.

Both bolts I had to remove on my motor.


Procedure above is pretty much the same for break style #2, Typically with that style break the die grinder and the "booger" step are not needed. Just weld the nut to the bolt.


Flame suit on.
 

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Nice write up, I do it the same way. Couple other tips.......turn the heat up on your welder and concentrate the weld on the center of the stud.....esp. the initial weld. This will heat and cool the stud....shrinking it and most the time allowing it to spin out nicely.

Also......I tack the nuts to the studs on any remaining that are not broken (esp. on the Fords) that way the stud comes out and you don't have to waste time pulling the stud once the nut is off.
 

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Whoop Whoop
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Nice write up, I do it the same way. Couple other tips.......turn the heat up on your welder and concentrate the weld on the center of the stud.....esp. the initial weld. This will heat and cool the stud....shrinking it and most the time allowing it to spin out nicely.

Also......I tack the nuts to the studs on any remaining that are not broken (esp. on the Fords) that way the stud comes out and you don't have to waste time pulling the stud once the nut is off.
We've had great success at the family shop with the weld technique. We have also heated the head around it and shot a quality penetrant/lubricant around the pesky bolt or oftentimes, pin on heavy equipment.

I'm talking tri lube or wurth (worth?) rost off.
 

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Little Member
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I used the weld nut trick on many projects. Don't know if it is the heat from the welder helping or not, but it works.
 

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Durango-space-division
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I tried this on my 360 heads. Lets just say I'm using 318 heads now :sonicjay:
You'll have a good low to mid range, but you'll suffer in the top end with those 318 heads. How bad did you screw the stockers? :sonicjay:
 

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I learned this trick from my father years ago. He owned many ford highboys with Fe eninges and they are quite possibly the worst head ever for breaking of manifold bolts. As frdboy said crank up the welder heat. There has even been times when the stud is broke off in the head more than just a couple of threads. When that occurs i bulid up the booger with the tig welder since i can get in a bit further than i can with the mig.
 

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Hoggin'-N-Boggin'
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2,358 Posts
great little tech tip, learned this when I was 22ish, first dana 60!! I broke the studs off flush the knuckle at the steering arm, took them iron mikes on dort highway to be removed he welded a nut to it and spun it out, best of all it was for free, not only I got free labor but I got a trick for my repertoire..hah
 

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I was told to use this method for my broken crossmember bolts. Hopefully it works as good. Thanks for the write-up.
 

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Live Action!
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I have 2 to do on my truck, the rear ones on both side. But it looks like just the heads popped off.

Do you use antisieze when installing new bolts and are the new bolts any better that what the factory used?

What should I expect when removing the lower manifold bolts at the exhaust pipe?
 

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Discussion Starter · #16 ·
15mm deep socket and extension, sometimes a wobble end makes it easier. depending on the year, the pass converter could be in the way of the flange bolt so I use a wrench from the wheel well if it is.

They make a bolt kit to replace all the bolts. I use 10.9 grade 8x1.25x30mm bolts with a lock washer. Haven't ever had one come back with an issue related to the repair. And I don't use antiseize on the threads.
 

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Live Action!
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15mm deep socket and extension, sometimes a wobble end makes it easier. depending on the year, the pass converter could be in the way of the flange bolt so I use a wrench from the wheel well if it is.

They make a bolt kit to replace all the bolts. I use 10.9 grade 8x1.25x30mm bolts with a lock washer. Haven't ever had one come back with an issue related to the repair. And I don't use antiseize on the threads.
Will I need a torch to get the lower bolts out? I would guess so but haven't done it yet.

The bolts you use are from the kit?

Thanks :beer:
 

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Discussion Starter · #18 ·
No, I use the bolts we keep in bulk at work.

Sometimes the torch is needed for the flange bolts., but not always.
 
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