# Broke manifold bolts, again



## johnslawn (Nov 13, 2006)

Folks, I replaced the broken exhaust manifold bolts almost two years ago. leaking.
/broken again. I understand it is a common chevy problem.
Anyone have better luck doing a fix? Suggestions? I really don't want to do this every two years. Thanks for input.
2006, 6.0 1 ton.


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## Sydenstricker Landscaping (Dec 17, 2006)

I guess the first question is where did you get the replacement bolts?? If they are dealer ones, of course they are gonna break again. I got a set of the stage 8 locking header bolts (they will work on the manifolds too) from summit last year. Even after a season of plowing and all this year with them, still look like the day I installed them. They dont list an actual 6.0 set, but the LS1 work just fine.


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## johnslawn (Nov 13, 2006)

Company mechanic did me a favor.Former GM tech. not sure what bolts he used. So your telling me to get quality bolts? Sounds feasible.


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## PlowTeam5 (Nov 14, 2010)

http://www.jegs.com/p/ARP/ARP-Header-Bolt-Kit/744888/10002/-1

Arp is a really good strong bolt.


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## johnslawn (Nov 13, 2006)

Ok. I will check with them to make sure they will go on stock manifolds. How bout gaskets? make a difference?


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## Sydenstricker Landscaping (Dec 17, 2006)

It wouldnt hurt to replace the gaskets. Has there been any leaking from the bolts being broke?? If so, you should also check the gasket surface of the manifold. The leak can distort the surface and cause more issues later down the road. But getting a high quality bolt from ARP or Stage 8 will be 10x better. Either one should fit the stock manifolds since they really arent much different than the headers and the bolts are the same length as the oem ones.


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## PlowTeam5 (Nov 14, 2010)

I would run a 3 piece steel gasket if I was you. They last alot longer then the paper ones. Or get a stock replacement as they have steel in them as well. The Felpro paper gaskets are junk IMO. I ran tons of 3 piece steel manifold and head gaskets and never had any issues with them. Another thing you can do to them is spray them down with Halamar before putting them on. That will help get a good seal. I have done this on many LS1 motors that I have built it never had a gasket go bad.


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## PlowTeam5 (Nov 14, 2010)

Here did all the work for you. 

http://www.cometic.com/domesticauto.aspx

Also if you can wait till monday you can call a local shop to me that my good friends own. They might be able to get you a good deal on everything or it at cost. 614-444-5884. Ask for Brandon or Jeff. Jeff is the owner. Tell them Sam sent you and they can hook you up. The shop is called IPS Motorsports and they do tons of LSX stuff. They have the fastest C6Z in the country.


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## johnslawn (Nov 13, 2006)

All good stuff guys. Thanks


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## 03silverado (Nov 28, 2010)

When the manifold is off, have it resurfaced to make sure it is flat. Also drill all manifold bolt holes to the next drill size. Especially the ones that are not round. What happens is when the manifold expands and contracts with the heat/cool cycle, the manifold pushes on the studs laterally, finally breaking them. Making the holes a little bigger lets the manifold shrink and grow without binding on the bolts. Started doing this 15 plus years ago on caterpillar engines. Works on all exhaust manifolds, Fords too!


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## johnslawn (Nov 13, 2006)

That sounds expensive to have done. And more than I am capable to do in my driveway. 
Talking with my brother today about stronger bolts installed. He mentioned, if I have problems in the future drilling stronger bolts out could be a problem. Made me think.


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## PlowTeam5 (Nov 14, 2010)

You can put anti seize on any bolt to keep it from sticking in the future to make for easy removal.


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## 03silverado (Nov 28, 2010)

Caterpillar tried the stronger bolt thing. They used high grade stainless. Those were horrible to drill and extract. They then said to drill holes bigger in the manifold and use the regular studs. Problem solved. Having manifold machined-35 bucks, G.M. studs 20 bucks, drilling manifolds out-nothing, a couple of hours labor-??? Not really hard or expensive.


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## johnslawn (Nov 13, 2006)

Again, great info.


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## BlizzardBeater (Aug 29, 2010)

Drilling out any manifold bolts really suck. I've always had much better luck welding a nut onto the broken bolt. This can even be done if the bolt is broke less than flush! But yes, you have to fix the issue or you will be chasing this forever. Drilling out the manifold holes will allow the manifold to expand and contract without stressing the bolts laterally. This should be the last time you have to do it.


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## Holland (Aug 18, 2010)

6.0's are notorious for breaking manifold bolts. especially the rear ones on each side. ( which of course are the hardest to get to) From the factory the manifold bolt holes are tight to the bolts. When the manifolds heat up they expand and what happens over time is they actually have a shearing effect on the bolts. best fix is to drill out the holes to the next size like 03 silverado stated. Felpro gaskets will be a little more forgiving and not require resurfacing. Use the factory steel ones and you might want to look into resurfacing. Hope it works out!


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## auto tech (Nov 30, 2010)

03 silverado nailed it xtract broken stud put gm bolts back in xcept enlarge the holes to give room to expand and contract,wouldnt recommend the grade 8 bolts if they cause when they break again youll have $500 in drill bits and either commit suicide or burn the truck.


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## johnslawn (Nov 13, 2006)

Truck going to the shop in a couple of weeks. Manifolds getting drilled, resurfaced and new exhaust installed.
Should be good for a few years. Fingers crossed.


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