One of my bolts that passes through the sombrero and holds the cross member to the chassis is seized in place, the head is sheared off, and the threads are stripped off. Does anyone have suggestions for how to proceed?
- Ryan
- Ryan
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Re: stripped bolt through sombrero
cut off wheel flush, drill and tap. use solid carbide drills will speed up process as this is at least a grade 5 bolt.
center drill as perfect to center as possible. -
Re: stripped bolt through sombrero
Gene,
If it's the original bolt it's a grade eight application. How about some kroil for a few days and a torch to heat the captured nut, you may get lucky.
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Re: stripped bolt through sombrero
If you have a blue wrench, I'd go with Tim's suggestion first. There appears to be enough of a stub left to get a small pipe wrench on.
Heat the threaded nut area of the sombrero interface, not the bolt stub.
Also, be careful to keep the torch away from the gas tank and fiberglass floor pan...
tcLast edited by Tracy C.; April 4, 2011, 11:23 AM.Comment
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Re: stripped bolt through sombrero
Ryan,
I too would go after it with a torch -- a real one, not propane. First you are going to have to get that rubber bushing out of there, and that will be a challenge all to itself. I would work with a Sawzall to make a vertical cut in the rubber and see if I could peel the rubber out of there. That will be necessary to get a reentrant (Kroil or PB Blaster) to the threads. Then the Oxy/Acetylene torch to the nut. Cautions about the fuel and fuel tank apply.TerryComment
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Re: stripped bolt through sombrero
Ryan, whatever you do use the cutting it flush as a last resort, hardened bolts don't drill easy, being here in the northeast, Rust is a big problem with older cars, if you can do as a few others quoted heating is the best way, getting the area around broken bolt glowing orange. then maybe a set of vise grips.New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.Comment
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Re: stripped bolt through sombrero
Use the kroil and then use vise grips but try tightening the remaining threads first to see if it will break free (no pun intended). Then you may be able to remove it, even if you need to keep applying the Kroil and working int back and forth.
DonOThe light at the end of the tunnel has been turned off.Comment
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Re: stripped bolt through sombrero
"Flaming Blue Point" wrench would be my choice. First make sure you have no fuel leaks and then heat cherry red. I have had very good success doing that. Cutting off and drilling would be my last resort. I am too old and feeble to put up with that much punishment.
Penetrating oil, if you have plenty of time works fairly well. I am having good success using Kroil on bolts on a vehicle that has sat outside for over twenty years since I bought it, and was driven thru the mountains of MD and WV for years before I bought it. So far I have over a gallon can of fasteners that I have removed without breaking one.
Remember patience is a major virtue when you are working on any restoration.Dick WhittingtonComment
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Re: stripped bolt through sombrero
Am I missing something here? This looks like a classic case of getting a plain nut one size bigger, placing it over the broken off bolt and welding it on with a regular arc welder. This method has been reviewed on just about every other automotive forum I have been on and seems to be the best method for this sort of thing. The heat of the welding causes everything to expand, and when it cools, it should just come out. This works for bolts broken flush with the surface as well. If it doesn't come out the first time, just get another nut and weld it back on. I could post a bunch of links to posts about this if I need to. Just let me know.Comment
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Re: stripped bolt through sombrero
It is a very awkward place to have to drill a broken bolt out it wrings off. I like your method for most situations, but a grade 8 over your head is very hard to drill if you break it off flush.
Patience, Patience, PatienceDick WhittingtonComment
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Re: stripped bolt through sombrero
I have used that method as well, but the OP didn't say he had any access to a welder.The light at the end of the tunnel has been turned off.Comment
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Re: stripped bolt through sombrero
Great discussion. Thanks for suggestions. I have few follow-up questions:
1) I have tried PB Blaster to no avail. I wouldn't expect Kroil be much if any better than PB Blaster?
2) How long is this bolt? Does it extend all the way through the sombrero and the plates of the frame that are supporting the sombrero? If so, seem like drilling out a Gr 8 is going to be pretty hard to do upside down.
3) So, I like Dennis's approach of welding on the nut. Dennis, could you point me to the other sites that show some detail on how they have done this in past? I'm wondering where/how they did the weld in order to get enough bead to withstand the torquing.
4) Do I need to be concerned about the flamability of prior applications of the PB blaster when I do the weld?
- RyanComment
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Re: stripped bolt through sombrero
Links :
http://www.reds-headers.com/html/red...e_talk_22.html
The responses you want are a few posts down. A couple of things to mention :
1. Use an impact to remove the bolt if possible. The intermittent "hammering" works better to remove fasteners than steady pressure.
2. Most of these guys are working on a lot older and rustier stuff than these Corvettes, and they seem to have a great deal of success with this method.
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Re: stripped bolt through sombrero
Dennis, thanks for the links. They are helpful for planning the job.
- RyanComment
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