need some help badly - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Lightspeed · 10-30-2002, 07:53 PM

i just changed the thermostat in my 70 model 350.
the passenger side bolt had about three washers on it, after i put the thermostat in i couldn't get the passenger side bolt to go back in, the threads are stripped out or something. it just won't tighten up. is there any way to fix this?

JoetheMobster · 10-30-2002, 08:02 PM

You could try and use some helicoils to repair it. Maybe you could try and use some JB Weld (or similar product) to repair it as well.

Lightspeed · 10-30-2002, 08:10 PM

do the threads go into the block or the intake?

Gordo · 10-30-2002, 08:16 PM

Go to your local parts store and get a heli-coil repair kit for that size bolt/thread. The kit will give you everything you need to do a excellent job.

*Zkast* · 10-30-2002, 08:21 PM

The bolts and threads will build up corrosion, to the point of a seized bolt = broken bolt.

Pull the bolt back out and inspect the threads (intake and bolt) if the threads in the intake look buggered, run a tap down through the hole. If the threads on the bolt look bad, replace it. If the threads in the intake are stripped or gone, you'll need to helicoil the hole. Machine shops can do this if you dont feel up to it. If its just corrosion, clean the bolt AND blow out any corrosion/dust thats left in the intake hole then install.

More common than not we see corrosion on the bolt, so bad that it doesnt allow the bolt to thread back in. If you have some antiseize around, use that to keep this from happening again. It's mainly made for aluminum but works great for steel corrosion problems also.

Lightspeed · 10-30-2002, 08:52 PM

well you can spin the wrench all you want and it will never tighten, would corrosion cause that?

*Randy70C-10* · 10-30-2002, 09:07 PM

Why are there 3 washers? Try taking 2 of them off and see if it will tighten.

**COBALT** · 10-30-2002, 09:07 PM

My money's on it being stripped. The same damn thing happened to me last time I tried to replace my thermostat. Both bolts were rusted badly, and both broke inside the manifold. One I was able to turn out, but the other wouldn't budge. Sorry to say I ended up pitching the manifold and went with a replacement (it was just a 327 2bbl - there's tons out there). The port flanges were messed up anyway.

I drilled and tapped it for a new set of threads, but those didn't hold up very well. The bolt would tighten but it was too loose, and I ended up stripping it again by accident. I also had to seal it against coolant. With the smallblock intakes, especially the cast-iron ones, the threads are set into a section of the intake where hot fluid sits right underneath. If you drill into that jacket you'll have a hell of a time getting the threads to seal. Like I said before I just gave up and swapped in a new manifold.

Good luck.

*Randy70C-10* · 10-30-2002, 09:14 PM

lightspeed- where do you live?

Lightspeed · 10-30-2002, 09:30 PM

near roanoke VA

10-30-2002, 07:53 PM	#1
Lightspeed Registered User Join Date: Oct 2002 Location: Virginia Posts: 226	need some help badly i just changed the thermostat in my 70 model 350. the passenger side bolt had about three washers on it, after i put the thermostat in i couldn't get the passenger side bolt to go back in, the threads are stripped out or something. it just won't tighten up. is there any way to fix this?

10-30-2002, 08:02 PM	#2
JoetheMobster Listening since '86 Join Date: Sep 2001 Location: Canada Posts: 1,799	You could try and use some helicoils to repair it. Maybe you could try and use some JB Weld (or similar product) to repair it as well. __________________ 2007 Saturn Aura - hey it WAS a GM product

10-30-2002, 08:16 PM	#4
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	Go to your local parts store and get a heli-coil repair kit for that size bolt/thread. The kit will give you everything you need to do a excellent job. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

10-30-2002, 08:21 PM	#5
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	The bolts and threads will build up corrosion, to the point of a seized bolt = broken bolt. Pull the bolt back out and inspect the threads (intake and bolt) if the threads in the intake look buggered, run a tap down through the hole. If the threads on the bolt look bad, replace it. If the threads in the intake are stripped or gone, you'll need to helicoil the hole. Machine shops can do this if you dont feel up to it. If its just corrosion, clean the bolt AND blow out any corrosion/dust thats left in the intake hole then install. More common than not we see corrosion on the bolt, so bad that it doesnt allow the bolt to thread back in. If you have some antiseize around, use that to keep this from happening again. It's mainly made for aluminum but works great for steel corrosion problems also. Last edited by Zkast; 10-30-2002 at 08:25 PM.

10-30-2002, 09:07 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	My money's on it being stripped. The same damn thing happened to me last time I tried to replace my thermostat. Both bolts were rusted badly, and both broke inside the manifold. One I was able to turn out, but the other wouldn't budge. Sorry to say I ended up pitching the manifold and went with a replacement (it was just a 327 2bbl - there's tons out there). The port flanges were messed up anyway. I drilled and tapped it for a new set of threads, but those didn't hold up very well. The bolt would tighten but it was too loose, and I ended up stripping it again by accident. I also had to seal it against coolant. With the smallblock intakes, especially the cast-iron ones, the threads are set into a section of the intake where hot fluid sits right underneath. If you drill into that jacket you'll have a hell of a time getting the threads to seal. Like I said before I just gave up and swapped in a new manifold. Good luck. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

10-30-2002, 08:10 PM	#3
Lightspeed Registered User Join Date: Oct 2002 Location: Virginia Posts: 226	do the threads go into the block or the intake?

10-30-2002, 08:52 PM	#6
Lightspeed Registered User Join Date: Oct 2002 Location: Virginia Posts: 226	well you can spin the wrench all you want and it will never tighten, would corrosion cause that?

10-30-2002, 09:07 PM	#7
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	Why are there 3 washers? Try taking 2 of them off and see if it will tighten.

10-30-2002, 09:14 PM	#9
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	lightspeed- where do you live?

10-30-2002, 09:30 PM	#10
Lightspeed Registered User Join Date: Oct 2002 Location: Virginia Posts: 226	near roanoke VA

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