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I have tried to remove the body mount bolt several times. Used freeze out twice, no luck. Filled a glass jar with bolt loosen oil and placed it up around the bolt. After submerging the bolt and nut in loosening oil for a full week, it still did not break loose. So, I used a hacksaw and cut the bolt off. Thought I was home free, but was unable to back the rest of the bolt out of the hole. There is still something rusted to the bolt between the underside of the floor pan and the triangular frame section. So now what?
If I gradually grind the head of the bolt off, I most likely will still be unable to remove it completely. It will be left ratting around in between the floor pan and the triangular frame section. Given the difficulty with this one bolt, I dread even attempting to do a full body off repair. My only other thought is to cut of the triangular frame section. If this section is removed, will I have enough room to repair the fiberglass section of the floor pan where the seat belt anchor bolt broke out of as well as replace the seat belt reinforcement bracket? Any other ideas? Thanks in advance for your help.
How about hitting the head with an air chisel with a blunt tip a few times a day for a week or so along with more soaking. Some persistent shock and impact might help loosen the rust up.
If the body mount bolts are this rusted what does the rest of the frame look like? Very discouraging way to start a body off. Best of luck.
I was not looking to do a body off, I am just trying to repair the seat belt anchor bolt. The welded nut broke free from the bracket, which then led to a hole in the side of my floor plan. I then thought I would remove the body mount bolt and make a bracket with a hole in it to be held in place with a new body mount bolt. I would then attach my seat belt anchor plate to this modified bracket. But, I can not get the bolt out. The rest of the frame does not look that bad, just surface rust. The prior owner of my car, must have changed this bolt at some time. If you look at the post that I listed in my first message, it seems to be a much longer bolt. I do not think the body has ever been off of the frame, but this bolt must have been replaced at some time. Can any one comment if I could repair the floor pan and seat belt reinforcement bracket, by removing the triangular section of the frame. Then weld a new triangular frame piece. Thanks.
I was not looking to do a body off, I am just trying to repair the seat belt anchor bolt. The welded nut broke free from the bracket, which then led to a hole in the side of my floor plan. I then thought I would remove the body mount bolt and make a bracket with a hole in it to be held in place with a new body mount bolt. I would then attach my seat belt anchor plate to this modified bracket. But, I can not get the bolt out. The rest of the frame does not look that bad, just surface rust. The prior owner of my car, must have changed this bolt at some time. If you look at the post that I listed in my first message, it seems to be a much longer bolt. I do not think the body has ever been off of the frame, but this bolt must have been replaced at some time. Can any one comment if I could repair the floor pan and seat belt reinforcement bracket, by removing the triangular section of the frame. Then weld a new triangular frame piece. Thanks.
Dave, I have read your other posts on this topic and you are correct in one of your previous posts regarding this bolt. This bolt is not a part of the original seat belt attaching hardware. It is a bolt that someone has installed previously to anchor the outboard seat belt, apparently after the original mounting bolt broke off. This is what the UNDERBODY SEAT BELT REINFORCEMENT/anchor plate looks like. https://www.paragoncorvette.com/p-35...forcement.aspx
This reinforcing plate is riveted to the left rear corner of the floor pan with 8 aluminum rivets. The top edge of the above photo is where the seatbelt anchor bolt normally screws in (where you currently have a large hole in the outboard vertical of your floorpan). The hole in the center rear of the flat portion is where a PO drilled through the fiberglass floor pan, through the frame corner brace and put a bolt in.
Since this is what the # 3 Crossmember Frame Gusset - L.H. should look like, https://www.paragoncorvette.com/p-351489--3-crossmember-frame-gusset-lh.aspx
I'm guessing that someone added the corner brace you are working with.
Since the floor pan does not actually contact this corner brace, if you were to remove the bolt currently in the hole and replace it with a new one, you would also need to insert a spacer between the fiberglass floor pan and the corner brace to be able to tighten up the bolt. Otherwise, tightening the bolt will simply try to pull the seat belt anchor through the fiberglass.
A simple solution (short of removing the body from the frame) would be to first remove the remnants of the bolt and then to carefully remove the heads of the aluminum rivets that hold the original UNDERBODY SEAT BELT REINFORCEMENT by "pushing" the rivets out and removing the reinforcement. You should then be able to insert a new UNDERBODY SEAT BELT REINFORCEMENT in its place and pop-rivet it in place. Keep in mind that the original factory installed rivets really do little more than hold the reinforcement plates in position until the anchor bolts are screwed into place, effectively sandwiching themselves to the fiberglass. Since you will not be able to reinstall original rivets with the body on the frame, the 8 pop-rivets will hold it in place so that you can screw in the seatbelt anchor bolt. This should give you the majority of the structural integrity that you had originally holding the seatbelt in place until someone eventually performs a body off and can reinstall original rivets.
I have tried to remove the body mount bolt several times. Used freeze out twice, no luck. Filled a glass jar with bolt loosen oil and placed it up around the bolt. After submerging the bolt and nut in loosening oil for a full week, it still did not break loose. So, I used a hacksaw and cut the bolt off. Thought I was home free, but was unable to back the rest of the bolt out of the hole. There is still something rusted to the bolt between the underside of the floor pan and the triangular frame section. So now what?
If I gradually grind the head of the bolt off, I most likely will still be unable to remove it completely. It will be left ratting around in between the floor pan and the triangular frame section. Given the difficulty with this one bolt, I dread even attempting to do a full body off repair. My only other thought is to cut of the triangular frame section. If this section is removed, will I have enough room to repair the fiberglass section of the floor pan where the seat belt anchor bolt broke out of as well as replace the seat belt reinforcement bracket? Any other ideas? Thanks in advance for your help.
Dave (1964 L76 coupe)
Hi Dave
I don't know if this will be of any help but I had a bolt I count not remove. A previous owner tried to remove it and resorted to a chisel to try to turn it. Now you couldn't get a wrench on it good enough. I got a welder to help and he welded a similar bolt thread end to the *&)@&# bolt. Now with good access he got it out. BTW I got a set of 6 point box end wrenches...when you are working with old cars 12 point wrenches can round off the bolt heads. Well good luck.
Dave, I have read your other posts on this topic and you are correct in one of your previous posts regarding this bolt. This bolt is not a part of the original seat belt attaching hardware. It is a bolt that someone has installed previously to anchor the outboard seat belt, apparently after the original mounting bolt broke off. This is what the UNDERBODY SEAT BELT REINFORCEMENT/anchor plate looks like. https://www.paragoncorvette.com/p-35...forcement.aspx
This reinforcing plate is riveted to the left rear corner of the floor pan with 8 aluminum rivets. The top edge of the above photo is where the seatbelt anchor bolt normally screws in (where you currently have a large hole in the outboard vertical of your floorpan). The hole in the center rear of the flat portion is where a PO drilled through the fiberglass floor pan, through the frame corner brace and put a bolt in.
Since this is what the # 3 Crossmember Frame Gusset - L.H. should look like, https://www.paragoncorvette.com/p-351489--3-crossmember-frame-gusset-lh.aspx
I'm guessing that someone added the corner brace you are working with.
Since the floor pan does not actually contact this corner brace, if you were to remove the bolt currently in the hole and replace it with a new one, you would also need to insert a spacer between the fiberglass floor pan and the corner brace to be able to tighten up the bolt. Otherwise, tightening the bolt will simply try to pull the seat belt anchor through the fiberglass.
A simple solution (short of removing the body from the frame) would be to first remove the remnants of the bolt and then to carefully remove the heads of the aluminum rivets that hold the original UNDERBODY SEAT BELT REINFORCEMENT by "pushing" the rivets out and removing the reinforcement. You should then be able to insert a new UNDERBODY SEAT BELT REINFORCEMENT in its place and pop-rivet it in place. Keep in mind that the original factory installed rivets really do little more than hold the reinforcement plates in position until the anchor bolts are screwed into place, effectively sandwiching themselves to the fiberglass. Since you will not be able to reinstall original rivets with the body on the frame, the 8 pop-rivets will hold it in place so that you can screw in the seatbelt anchor bolt. This should give you the majority of the structural integrity that you had originally holding the seatbelt in place until someone eventually performs a body off and can reinstall original rivets.
Good luck... GUSTO
Gusto 14, thanks for taking the time to review my prior postings. However, you are still a little confused with my situation. This started when I tried removing my seats belts to restore them. The welded nut on the outboard seat belt reinforcement (as soon pictured in your reply) broke free while I was turning the seat belt anchor bolt. I eventual broke the bolts with the welded nut through the fiberglass floor pan. I know the best may to repair this to to remove the body, but I was trying to avoid this type of repair at this time. The 64 coupe has a body mount bolt that is attached to the frame gusset. The prior owner was not using this as a seat belt attachment. I am trying to use it as a temporary seat belt attachment, since I do not what to remove the body at this time.
I was unable to lossen the nut on this bolt, so I cut the bottom of the bolt off, thinking that I could remove it. However, there is something (most likely another washer) that seems to be rusted to the bolt. This washer is located above the gusset and below the floor pan. While at can freely turn the remaining bolt (including the bolt head), I can not remove it from the floor pan. My reason for removing the bolt was to make a temporary bracket that I could use to reattach my seat belt anchor. Since I can not get the remaining portion of the bolt out without busting up more of my floor pan, I was wondering if I could effectively remove the the frame gusset, grind off the washer that is preventing me from removing the cut off bolt and then perform the correct repair of the seat belt reinforcement bracket. Thanks.
Gusto 14, thanks for taking the time to review my prior postings. However, you are still a little confused with my situation. This started when I tried removing my seats belts to restore them. The welded nut on the outboard seat belt reinforcement (as soon pictured in your reply) broke free while I was turning the seat belt anchor bolt. I eventual broke the bolts with the welded nut through the fiberglass floor pan. I know the best may to repair this to to remove the body, but I was trying to avoid this type of repair at this time. The 64 coupe has a body mount bolt that is attached to the frame gusset. The prior owner was not using this as a seat belt attachment. I am trying to use it as a temporary seat belt attachment, since I do not what to remove the body at this time.
I was unable to lossen the nut on this bolt, so I cut the bottom of the bolt off, thinking that I could remove it. However, there is something (most likely another washer) that seems to be rusted to the bolt. This washer is located above the gusset and below the floor pan. While at can freely turn the remaining bolt (including the bolt head), I can not remove it from the floor pan. My reason for removing the bolt was to make a temporary bracket that I could use to reattach my seat belt anchor. Since I can not get the remaining portion of the bolt out without busting up more of my floor pan, I was wondering if I could effectively remove the the frame gusset, grind off the washer that is preventing me from removing the cut off bolt and then perform the correct repair of the seat belt reinforcement bracket. Thanks.
Dave
Dave, yes, I think if you do remove the frame gusset (which I don't believe is the correct one for your car) you should be able to do as you're wanting to do.
Having said that, if you do remove the current gusset, you will also be able to gain access to remove the old UNDERBODY SEAT BELT REINFORCEMENT/anchor plate as I suggested above and reattach a new one in it's place. You should be able to do this with some small stainless machine screws and lock nuts (or even pop-rivets if you choose) to hold the reinforcement in place. As I mentioned earlier, the original rivets really only hold the reinforcement in position so that you can screw in the anchor bolt. At that point the anchor bolt is holding the seat belt anchor tight against the reinforcement with the underbody sandwiched in between. Ultimately this is all that held the seat belts in the car originally.
At that point, I would replace the frame gusset with an original style gusset as pictured above.
One thing you may not be aware of is that the '63 frame did not even incorporate these corner gussets, at least not on the early cars. As part of a frame off on my '63 convertible, I removed all of the underbody reinforcements and replaced them with new ones and also added the corner gussets to my frame. While most of my reinforcements were in okay condition, they did exhibit a good deal of pitting that would have been unsightly in my opinion so I replaced them. With the help of a friend, I also reinstalled them with new aluminum rivets.
02-28-2015, 04:51 PM
Bolt removel problem keeps getting worse
