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LS manifolds

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Doing manifold gaskets for a friend on his 06 Denali with a 6.0. (Truck is mint, and gorgeous, and I'm kinda jelly of it.) I can see one broken bolt on the passenger side, I grabbed a wrench and the other bolts loosened up easy. I Just youtubed it and the video I watched the guy ripped out all the bolts with an impact and said they pop the heads off from heat cycling. The broken bolts he got out real easy with a stud puller.

What are your experiences doing these? Should I just put new manifolds on it right away? They are dirt cheap on Amazon, so that tells me that is the common fix.
 
Are they factory manifolds or repops?
 
I think it's got the factory ones still on it. Two Dorman manifolds and bolts are $180 shipped on Amazon.
 
It's pretty common for the bolts to break, not sure why. I haven't heard of a need to put on new manifolds just new gaskets and bolts and call it done.
 
We don't have to replace manifolds on those. Fix the broken stud, new gaskets and move on. They don't typically crack. The damn studs are undersized and they just break. Usually the back one on either side that you can't get at to drill and tap if it don't come out. There is a quick fix for that though. They sell a clamp that bolts to an unused hole on the back of the head and the next bolt in front of the last one. A third bolt comes through the bracket and just bottoms out on the manifold itself. Tighten snug and no more leak. I've had one on my 5.3 for almost 3 years now. No problems.
 
I have done a few.
Hopefully there is a piece of the bolt sticking out of the head. Mig a nut on the bolt and it will back right out.
If its flush or below the surface you will need to drill it out.
LEFT HAND DRILL BIT works very well, take your time, no easy-out required.
 
I had 3 broken exhaust manifold bolts on my 6.0 when I got it. It was much easier to get them out than I expected. Only tool I tried was the welder. I went through 2-3 nuts on one of them, but the other 2 backed right out after the first try. I kept the stock manifolds and replaced all the bolts with Dorman and it's been leak free for a couple years. It doesn't normally get driven much but I did tow a camper across the country and back with it and the bolts have stayed tight.
 
gm manifolds are o.k. to reuse most the time . ford tho = crap after the heads pop .

early gm manifold bolts were 10mm socket . newer bolts are 13mm socket .

lots of guys are now changing the bolts only 1 at a time after a year or so to help avoid the popped head problem .

i will do gm ones all the time . i dont do ford pass side on ifs trucks . they suck donky nuts .
 
Right side manifold came off easy peasy yesterday. It had one broken bolt that came right out with a Vice Grips. Two new manifolds, gaskets, bolts, plugs and wires are in the mail and should be here tomorrow. Gonna pull the get back at it tomorrow after work.
 
also heard lots of guys saying the castings for china dorman manifolds suck for life span .

when i do them i get new bolts and 3 down pipe nuts and gaskets from gm .

the down pipe studs are triangle thread like a crimp lock nut . up here at least they need lots of heat and no impact just hand tools or they screw up and then your changing a stud also .
 
My friend has done a lot of 460 Ford manifolds,the bolts always snap off in the heads and its a bear to get them out--the method he uses with the best success is mig welding a nut to the broken bolt if any is still sticking out,but most of them snap below flush and the cylinder head metal is powdered iron and the bolts turn to diamond hard steel after so many heat cycles..

It makes trying to drill one out almost impossible,the bits keep skidding off into the head's softer metal..not much meat around the bolt holes either,so going oversize on the bolts is also a no-go most of the time..he now wont do any for less than $600 ,it ties up his lift for 2+ days most of the time..

GM was stupid to downsize the exhaust manifold bolts on the LS engines..he has to do a lot of those too,but most of the time they aren't that big a hassle to get the busted bolts out --but you cant even get a tool near the rear most ones that break most often..almost like they planned it that way..
 
sweetk30 said:
gm manifolds are o.k. to reuse most the time . ford tho = crap after the heads pop .

early gm manifold bolts were 10mm socket . newer bolts are 13mm socket .

lots of guys are now changing the bolts only 1 at a time after a year or so to help avoid the popped head problem .

i will do gm ones all the time . i dont do ford pass side on ifs trucks . they suck donky nuts .
Click to expand...

When did the change from 10MM to 13MM take place? I've got 230k on the og 5.3 in my 06, and no issue yet.
 
Sometimes the back bolts are broken off for years and there are no issues.
 
It's the drivers side rear that is broken. fighing it out now.
 
sweetk30 said:
temp yes ......... long term nope .
Click to expand...
OK dude. I guess 3 years is temporary. Mine hasn't leaked yet. I guess when it's the difference between pulling the head for access to remove the broken stud or putting the clamp on, I'll go this way.
 
That fix reminds me of the "Clamp-A-Stud" thing they came up with to let you get away with not replacing a busted manifold to Y-pipe stud..

It was a pretty clever inventions,basically a "C" clamp that has a sharpened pointed steel pin on the clamp side and a shouldered base on the threaded portion that seated in the exhaust pipe flange..

My friend had a Chevy come in his shop once years ago,that had four of them,two on each manifold!..we laughed a good 5 minutes when we saw that,the owner probably spent $50 on the clamps and could have had the studs replaced for about the same price..but they did work,there was no exhaust noise or leaks!..

When I sold these things they were less than $10 and everyone said they were a ripoff...look what they cost now!..:eek:
Nickson Clamp-A-Stud 1-1/4" - 2-3/4", (Sp) 631275: Advance Auto Parts
 
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