exhaust stud removal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*Fast68Chevy* · 06-29-2002, 11:26 AM

anyone who has any good tips regarding removing frozen and busted off flush exhaust flange studs please post their info here

got one thats busted off flush that i gotta get out, worst case scenario is that I would have to drill out 3/8" and use nut and stud....

Southpa · 06-29-2002, 11:53 AM

The last resort is drilling, they just never seem to fit right after that. Unless you can drill it out at a near perfect right angle to the flange and tap it for a larger size stud. The steel they use for these things is extremely hard, went thru a couple drill bits (with numerous resharpenings in between) just on one hole.

Best bet is to drill part way w/ a smaller size bit than the hole. Then heat the hell out of it with a torch, squirt penetrating oil and use an "easy-out".

boilrman · 06-29-2002, 12:12 PM

I had to do this to the exhaust manifold on my I6. Believe it or not I actually got one of them to screw out.(lots of PB, LOL) the other snapped when I tried to remove it.

First grind it off flush, find the center of the stud and centerpunch it. Then start with a small drill bit and go through it and slowly increase size of bit. Then get a easy out and hope the remaining metal comes out. If not, you can retap the hole.

**StingRay** · 06-29-2002, 12:29 PM

Take it to somebody with a mig welder and put a nut over what is left of the stud. If the stud is flush carefully build up the stud with the mig until you have enough to weld to. Weld the nut on and the heat from that will likely have loosened the threads. Just turn it out with a wrench then. If that fails drill and easy out but use some heat to help loosen the threads.

tom hand · 06-29-2002, 01:17 PM

I aways grind them flush, drill them out, then use helicoils. You don't have to drill it perfect because you are going to tap it out to a bigger size for the helicoil. After you install it it is back to the correct size and the threads are now stainless steel so no more problems. When you get new studs, get the kind that come with brass nuts.

**JIMs70GMC** · 06-29-2002, 05:08 PM

Use a reversible drill and reverse cut bits for your drilling and it might spin it's self out, if not you'll have your hole for easy-outs. I did this once and when I moved up in bit size it spun it out.

70 Jimmy · 06-29-2002, 05:30 PM

If you use stainless helicoil, don't use stainless studs. Stainless +stainless + heat = gauling. Bad news.

*Fast68Chevy* · 07-06-2002, 06:52 PM

thanks guys, well im gonna try drill and EZ out and heat and hope for best, only bad thing about heat is that heat changes properties of metals and makes them brittle, so,,,
but have no choice really,,,

thanks

mrein3 · 07-06-2002, 08:52 PM

What I have done in the past is this:

Drill the stud to the size you need for an E-Z out. don't tap in the E-Z out yet

Get your fire-wrench out and get the manifold red hot. Try not to focus the heat on the stud.

Now you have to move fast.
Tap in the E-Z out and back out the remains of the stud.

Cool things down, clean the threads, and put in a new stud.

*Fast68Chevy* · 09-05-2002, 03:32 AM

awesome, thats very good info for the memory bank, now lets move over to broken 3/8" bolt in exhaust manifold mounting bolt snapped off in the (same bolt) hole in the head ?

3/8" with 16 tps helicoil ?
what size tap do you have to use for 3/8" coil anyways?

thats my Q, i have two i need to fix... asap.

who has done it ?

thanks for anything

Mike C · 09-05-2002, 08:38 AM

Unlike the manfold stud that bottoms out on its "neck" when you tighten it down, the broken bolt in the head should NOT be, unless someone used the wrong bolt. Get yourself a reverse cut drill bit or one of the combo drill/srew removers and it SHOULD spin right out... but you know how that is

All of the stress is off the threads once the bolt breaks, but the stress remains on the stud after it breaks because the shoulder is still snug against the manifold face.

*Fast68Chevy* · 09-05-2002, 02:31 PM

wow, good point there, thanks!@

wel the problem is that the bolts snapped off in the head due to severe corrosion, so the odds of them spinning right out are very very slim,..
they are frozen corrode welded to in the bolt holes bad, must be a big block engien problem, never had it happen on a SBC engine

thanks

06-29-2002, 11:26 AM	#1
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	exhaust stud removal anyone who has any good tips regarding removing frozen and busted off flush exhaust flange studs please post their info here got one thats busted off flush that i gotta get out, worst case scenario is that I would have to drill out 3/8" and use nut and stud....

06-29-2002, 11:53 AM	#2
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	The last resort is drilling, they just never seem to fit right after that. Unless you can drill it out at a near perfect right angle to the flange and tap it for a larger size stud. The steel they use for these things is extremely hard, went thru a couple drill bits (with numerous resharpenings in between) just on one hole. Best bet is to drill part way w/ a smaller size bit than the hole. Then heat the hell out of it with a torch, squirt penetrating oil and use an "easy-out". __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

06-29-2002, 12:12 PM	#3
boilrman 70 Chevy 3/4t Join Date: Sep 2000 Location: Kokomo,IN USA Posts: 1,230	I had to do this to the exhaust manifold on my I6. Believe it or not I actually got one of them to screw out.(lots of PB, LOL) the other snapped when I tried to remove it. First grind it off flush, find the center of the stud and centerpunch it. Then start with a small drill bit and go through it and slowly increase size of bit. Then get a easy out and hope the remaining metal comes out. If not, you can retap the hole. __________________ Find a job you love and you'll never have to work a day in your life. 1998 Yamaha V-Star 650 1970 Chevy 3/4t, I6 (rebuilt), 4 speed Kokomo,IN

06-29-2002, 12:29 PM	#4
StingRay Senior Member Join Date: Mar 2000 Location: Saskatoon,SK,Canada Posts: 2,476	Take it to somebody with a mig welder and put a nut over what is left of the stud. If the stud is flush carefully build up the stud with the mig until you have enough to weld to. Weld the nut on and the heat from that will likely have loosened the threads. Just turn it out with a wrench then. If that fails drill and easy out but use some heat to help loosen the threads. __________________ Saskatoon, Saskatchewan Canada

06-29-2002, 01:17 PM	#5
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I aways grind them flush, drill them out, then use helicoils. You don't have to drill it perfect because you are going to tap it out to a bigger size for the helicoil. After you install it it is back to the correct size and the threads are now stainless steel so no more problems. When you get new studs, get the kind that come with brass nuts. __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

06-29-2002, 05:08 PM	#6
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Use a reversible drill and reverse cut bits for your drilling and it might spin it's self out, if not you'll have your hole for easy-outs. I did this once and when I moved up in bit size it spun it out. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

06-29-2002, 05:30 PM	#7
70 Jimmy aka Crusher, Crushergmc Join Date: Mar 2000 Location: Oregon Posts: 1,834	If you use stainless helicoil, don't use stainless studs. Stainless +stainless + heat = gauling. Bad news. __________________ "KEEP IT DOWN!" 70 Jimmy 454 2wd 56 GMC Big Window "It's funny till someone gets hurt, then it's freakin' hilarious"

07-06-2002, 06:52 PM	#8
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	thanks guys, well im gonna try drill and EZ out and heat and hope for best, only bad thing about heat is that heat changes properties of metals and makes them brittle, so,,, but have no choice really,,, thanks

07-06-2002, 08:52 PM	#9
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	What I have done in the past is this: Drill the stud to the size you need for an E-Z out. don't tap in the E-Z out yet Get your fire-wrench out and get the manifold red hot. Try not to focus the heat on the stud. Now you have to move fast. Tap in the E-Z out and back out the remains of the stud. Cool things down, clean the threads, and put in a new stud. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

09-05-2002, 03:32 AM	#10
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	awesome, thats very good info for the memory bank, now lets move over to broken 3/8" bolt in exhaust manifold mounting bolt snapped off in the (same bolt) hole in the head ? 3/8" with 16 tps helicoil ? what size tap do you have to use for 3/8" coil anyways? thats my Q, i have two i need to fix... asap. who has done it ? thanks for anything

09-05-2002, 08:38 AM	#11
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,723	Unlike the manfold stud that bottoms out on its "neck" when you tighten it down, the broken bolt in the head should NOT be, unless someone used the wrong bolt. Get yourself a reverse cut drill bit or one of the combo drill/srew removers and it SHOULD spin right out... but you know how that is All of the stress is off the threads once the bolt breaks, but the stress remains on the stud after it breaks because the shoulder is still snug against the manifold face. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

09-05-2002, 02:31 PM	#12
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	wow, good point there, thanks!@ wel the problem is that the bolts snapped off in the head due to severe corrosion, so the odds of them spinning right out are very very slim,.. they are frozen corrode welded to in the bolt holes bad, must be a big block engien problem, never had it happen on a SBC engine thanks



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