Did my frame just bend?
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
Did my frame just bend?
OK so I am jacking up my car and since I learned about my c4 jack points I looked into the proper c3 ones and not been jacking my c3 from the center front. I have been using the side frame rail just before it turns in and putting the stand under the shocks. I always jack each side a few pump and go to the other.
Anyways so I am jacking the pass side(lower side atm) and there is a loud bang that resonates thru the car. I know the jack didn't slide/slip or anything like that my jack pads are flat!
I looked all over for any tears or popped welds and I'm not usre if the frame was always like it is but it looked kinda funny to me and I do have a pretty good visual memory. So I snapped some pics(not the best) and maybe someone can look at their frame. Car is a 77
Pass side near firewall where the AC/heater use to be, factory fuel lines covered in heat shielding. Circle shows bulging area.
Diff angle
By the pass motor mount
Maybe I just rem things wrong but I spent a lot of time in this area under/above.
Anyways so I am jacking the pass side(lower side atm) and there is a loud bang that resonates thru the car. I know the jack didn't slide/slip or anything like that my jack pads are flat!
I looked all over for any tears or popped welds and I'm not usre if the frame was always like it is but it looked kinda funny to me and I do have a pretty good visual memory. So I snapped some pics(not the best) and maybe someone can look at their frame. Car is a 77
Pass side near firewall where the AC/heater use to be, factory fuel lines covered in heat shielding. Circle shows bulging area.
Diff angle
By the pass motor mount
Maybe I just rem things wrong but I spent a lot of time in this area under/above.
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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2016 C3 of Year Finalist
How are your door seams? Any cracks in your paint anywhere? That picture could have been like that. A loud noise would mean a structural fail ( weld popping or cracking, bolt snapping,etc) Bulging without a structural fail won't make noise. I had a jack stand slide on a front shock mount before and it made a loud noise that nearly stained my pants. If your seams are good and the nose is still straight it was probably the stand shifting on the ground. On my convertible the door seam at the back of the door moves abit so that shouldnt be an indicator unless the gap is big.
Can you reach the top of the bulge or see it from above?
Can you reach the top of the bulge or see it from above?
Last edited by Rescue Rogers; Apr 24, 2016 at 09:41 PM.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
It was before the stands were even under the car and I was still jacking. The above pics I took don't show it but it's visible from the top.
Looks like I'll be crawling all around under the car for the next few days then. I don't wanna find out at 100+
Looks like I'll be crawling all around under the car for the next few days then. I don't wanna find out at 100+
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,222
Likes: 9,359
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Ya, good idea
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
Yah more I think about your right Rogers bang is a bolt, weld or maybe even something cast like the bell housing. Since the rear was on the ground I'll deff check it all out there.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,392
From: At my Bar drinking and wrenching in Lafayette Colorado
There's no way you can bend a C3 frame by jacking it, no matter where your jacking point is. When we pull the frames on our frame machine, we have to chain them down and apply loads that are over 4 times the weight of the vehicle in order to get a frame rail to move. Jacking one side of the car, you're barely getting 1/2 the weight of the car as a reaction load, and that frame isn't going to yield with only 1700 pounds of force on it.
Lars
Lars
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Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
I just rem seeing a few pics of c3 frames cracked around the front area and I investigated the area I was jacking. My whole frame is about filled with mouse nest so who knows how bad the rust is inside.
Makes more sense now to look towards the rear and I will soon as I finish up in the front. More I think about it the bump may have always been there, just tired and being cautious. Thanks for the replies and reassurances.
Makes more sense now to look towards the rear and I will soon as I finish up in the front. More I think about it the bump may have always been there, just tired and being cautious. Thanks for the replies and reassurances.
Last edited by BOOT77; Apr 25, 2016 at 02:46 AM.
Drifting
Joined: Dec 2011
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From: Chardon Ohio
There's no way you can bend a C3 frame by jacking it, no matter where your jacking point is. When we pull the frames on our frame machine, we have to chain them down and apply loads that are over 4 times the weight of the vehicle in order to get a frame rail to move. Jacking one side of the car, you're barely getting 1/2 the weight of the car as a reaction load, and that frame isn't going to yield with only 1700 pounds of force on it.
Lars
Lars
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I would follow the frame rails both sides to the front end. Sometimes they crack about where the wheel sits. And if it is that it is quite fixable.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
Yup I'm thinking Ill take a good look at my 1yr old vbp fiberglass spring and the diff mounting ears that break. Soon as I get the front back together. I was only jacking it up so it wouldn't continually poor gas, forgot to buy some 6an caps for when I have the lines off my new fuel pump.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
if you are using a trolley jack, it probably just shifted on the metal pad. happens all the time and is scary. the jack has wheels on it because it has to move continuously and slide under the fulcrum as it lifts. if the little wheels get stuck, on rocks, or whatever, the vehicle can shift on the lift pad fingers and make a loud bang.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,222
Likes: 9,359
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
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Have you discovered anything that may be damaged?
Racer
Joined: Sep 2012
Posts: 459
Likes: 6
From: Fort Worth Texas
OK so I am jacking up my car and since I learned about my c4 jack points I looked into the proper c3 ones and not been jacking my c3 from the center front. I have been using the side frame rail just before it turns in and putting the stand under the shocks. I always jack each side a few pump and go to the other.
Anyways so I am jacking the pass side(lower side atm) and there is a loud bang that resonates thru the car. I know the jack didn't slide/slip or anything like that my jack pads are flat!
I looked all over for any tears or popped welds and I'm not usre if the frame was always like it is but it looked kinda funny to me and I do have a pretty good visual memory. So I snapped some pics(not the best) and maybe someone can look at their frame. Car is a 77
Pass side near firewall where the AC/heater use to be, factory fuel lines covered in heat shielding. Circle shows bulging area.
Diff angle
By the pass motor mount
Maybe I just rem things wrong but I spent a lot of time in this area under/above.
Anyways so I am jacking the pass side(lower side atm) and there is a loud bang that resonates thru the car. I know the jack didn't slide/slip or anything like that my jack pads are flat!
I looked all over for any tears or popped welds and I'm not usre if the frame was always like it is but it looked kinda funny to me and I do have a pretty good visual memory. So I snapped some pics(not the best) and maybe someone can look at their frame. Car is a 77
Pass side near firewall where the AC/heater use to be, factory fuel lines covered in heat shielding. Circle shows bulging area.
Diff angle
By the pass motor mount
Maybe I just rem things wrong but I spent a lot of time in this area under/above.
Racer
Joined: Sep 2012
Posts: 459
Likes: 6
From: Fort Worth Texas
if you are using a trolley jack, it probably just shifted on the metal pad. happens all the time and is scary. the jack has wheels on it because it has to move continuously and slide under the fulcrum as it lifts. if the little wheels get stuck, on rocks, or whatever, the vehicle can shift on the lift pad fingers and make a loud bang.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I am of the belief that your saddle of your floor jack was the culprit in making the noise.
And not that what I do matters or not.....but for over 30 years I have been jacking up Corvettes from the center front and rear center differential area so I am lifting the front and rear clips evenly and have never had a problem. I RARELY use the side to side method..and if I do it is because the front end is so low and the car is not running where I can drive it up on my homemade ramps. Once I get it high enough to slide my ramps under it I do...then finish picking it up from the center front or rear. Then the 'trick' is properly placing the support stands so you do not allow the frame to sag...because it can....depending on rust issues, being a convertible ( rear clip sag concerns) or any previous 'stuff' that has happened to it in the past.
DUB
And not that what I do matters or not.....but for over 30 years I have been jacking up Corvettes from the center front and rear center differential area so I am lifting the front and rear clips evenly and have never had a problem. I RARELY use the side to side method..and if I do it is because the front end is so low and the car is not running where I can drive it up on my homemade ramps. Once I get it high enough to slide my ramps under it I do...then finish picking it up from the center front or rear. Then the 'trick' is properly placing the support stands so you do not allow the frame to sag...because it can....depending on rust issues, being a convertible ( rear clip sag concerns) or any previous 'stuff' that has happened to it in the past.
DUB
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,222
Likes: 9,359
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
A little interruption please while I got Dub standing here ( theoretically).
I do your method but just got a quick jack.
I have a 68 convertible that the rear sags a little when all 4 wheels are off the ground and supported from the frame. How long can I leave like this, weeks days months? Will it do any damage? I had I like this for a month this past winter and it didnt do any damage then, just want to know your opinion. Thanks. Now back to your show
I do your method but just got a quick jack.
I have a 68 convertible that the rear sags a little when all 4 wheels are off the ground and supported from the frame. How long can I leave like this, weeks days months? Will it do any damage? I had I like this for a month this past winter and it didnt do any damage then, just want to know your opinion. Thanks. Now back to your show
Last edited by Rescue Rogers; Apr 26, 2016 at 07:38 PM.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
My jack pads are flat with rubber pad! I'll take a pic if I have too but these are not the typical cup with the four teeth sticking up.
I use to use the center and would park/drive onto some 2x10's I cut to slide a jack under easier, but then I noticed the center is dented in from jacking. I read about some welding a plate to reinforce it but I prefer to try and keep my car light.
Edit: Not looked too much but I will when I'm done up front, need to check some stuff in the back anyway and change my rearend fluid.
I use to use the center and would park/drive onto some 2x10's I cut to slide a jack under easier, but then I noticed the center is dented in from jacking. I read about some welding a plate to reinforce it but I prefer to try and keep my car light.
Edit: Not looked too much but I will when I'm done up front, need to check some stuff in the back anyway and change my rearend fluid.
Last edited by BOOT77; Apr 26, 2016 at 08:49 PM.