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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: heyharris1 on March 07, 2009, 04:34:42 pm
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oki, here's the background, while doing my tranny job i know the flange gasket on the exhaust manifolds are shot. so i figure change them now so its easier. Well here's were it gets intresting. Taking the bolts loose from the flange 2 bolts came out 4 snapped off :-(. After playing for awhile with them i decide i beter take the exhause manifolds off to give me beter access to remove the broken studs. Exhaust manifolds actually came off easy, did not break one bolt.
Oki so i soak the broken studs in pb blaster, liquid wrench, wd-40, and according to my friend a mixture off accetone/atf. nothing will make these bolts move. and now worse since there was about a inch of bolt sticking out they have since broke and all 4 bolts are flush with the manifolds. think i might be done-in and have to go to a machine shop to get them removed. also i dont have a torch to heat them with.
next delima i was thinking replace them with new but the exhaust manifold are almost 200.00 each since they have extra hols in them for the air pup to inject air into them, only my quess why they are so much. other than those studs they are in excellent shape so would hate to replace them unless i have to. its not a race truck so stock is fine with me. it is a 1986 454
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Do you have a vise, decent drill and sharp drill bits? Drill them out, If you have to Heli Coil them. You can buy Heli Coil kits for more then one hole. Usually come six to a package, they come with a tap so all you need to do is drill the holes out to the size determined by the tap in the kit. Start small and sneak up on them. If you have access to left handed drill bits you might get lucky and they will spin out!
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Or just go ahead and call the local machine shop. It might be cheaper than you expect..
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I have had USA muffler replace studs while on the truck. Did not charge much to do it either.
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update.
well so far i have gotten 2 of them out by welding nuts onto the end, most of the time they just twist off but i found eventually it will turn just a hair, then i spray in the blaster and slowly work it back and fourth, 2 bolts about 3 hours. i think there winning. try to get the other 2 tomorrow as im now tired as heck.
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Some may consider this a hack job but I've had great luck with it.
A)Take a dremel tool with a cut off wheel and cut the broken studs off even with the manifold.
B)Get out your drill and drill out the studs (don't worry about wrecking the threads on the manifold,you won't use them).
C)Go to the hardware store and get some grade 8 hardware. You will need bolts about 1/2 longer than the studs,lock washers, and nuts.
D)Bolt the pipes back up from the bottom. You can still use the factory springs that were on the studs(they compensate for the expanding and contracting metal. Put the bolt through the spring/exhaust pipe/manifold/lock washer/nut/then use a second nut as a jam nut.
Like I said,it's not for everyone but it has saved me more than a few times.
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not a bad idea but it wont workin this situation, 2 of the holes are blind holes, not drilled all the way through. im not sure if this has been modified or not because there is no spring setup at all.
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I have a 1987 454 on an engine stand in my garage that has the springs on it. Maybe someone did exhaust work on your truck in the past and didn't replace the springs(sometimes people leave them out). Even if you have some blind holes I don't see any reason you could not drill through the manifold.
I can post some pics tomorrow of a repair like this i did on a truck awhile back, it's held up fine. The main advantage of this repair is that it is easy to do without removing the manifolds (i know yours are off now).
I see from your post that you have a welder, you could always drill out the stud and then cut the head off of the bolt and weld the threaded portion in the hole (this way you can use a grade 8 bolt).
Just trying to kick around a few ideas that would work without buying manifolds.
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Heyharris
After your done getting them out and reinstalling new bolts put some antiseize on the threads.It helps out a ton if you ever got to do his again in the future.
thanks
pat
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We've all been there. Sounds like you're digging out. What you need is a t-shirt from these guys. Notice the motto.
www.bustedknucklegarage.com (http://www.bustedknucklegarage.com)
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Brass nuts too.
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I checked out my big block, Your right about those blind holes. Theres no flange to drill through. Did you get them out yet? Like I mentioned before, you could always drill out the old stud and weld in the new one.
Heres a pic of a repair I made with the bolt method, it's been a while and it's held up fine.
Good luck.
Fitz.
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oki update number 2
got all the bolts out but one, it was really bad, took it to the local machine shop and he could not get it out either so just dilled the whole thing bigger and put in a heli-coil (spelling) looks good as new and only 25 bucks. o'well all better now and new gaskets also so no more exhaust leaks