I want to check out if my front coil springs are in need of replacement. I was advised to check in Service Manual and/or AIM for specs on checking out coil springs. Not sure I am looking at right section or which measurement to use. I see the section on trim heights but not sure how to use or if this is necessary or accurate without the original tires. I have both books so if someone can tell me eactly what and where it is appreciated. I have a 71 LS5 Coupe. Thanks again. Ed
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Re: Coil Springs *TL*
Ed,
One or both of those books will have measurements that require you to calculate the difference between the pivot point of the lower control arm and the outer point of the same control arm (by the ball joint). With non-original size tires you have to figure this dimension because it is the only one that ignores the height of the tire.
I will have to drag out those books so I can be more specific and I will post the letters they use after I have the books in front of me.
Terry
Terry -
Re: Coil Springs *TL*
Ed,
One or both of those books will have measurements that require you to calculate the difference between the pivot point of the lower control arm and the outer point of the same control arm (by the ball joint). With non-original size tires you have to figure this dimension because it is the only one that ignores the height of the tire.
I will have to drag out those books so I can be more specific and I will post the letters they use after I have the books in front of me.
Terry
TerryComment
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Re: Coil Springs
I thought it might be that measurement. It is 'Z' if I am correct. If it turns out that I need a new spring, which I fear I do, I assume I should change both sides to match. Also I have been warned to be very carefully with the loaded spring. what to you advise for the best tool and procedure? I read in Corvette Central that the back spring should have a bow. Mine is pretty straight with car weigh on it. They make a few types? How do you recommend checking rear spring and what type is best for a good restored driver? It seems to me if I use a good tool and follow directions I can change coil spring without hurting myself even though I never did it before. Does that sound reasonable?Comment
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Re: Coil Springs
I thought it might be that measurement. It is 'Z' if I am correct. If it turns out that I need a new spring, which I fear I do, I assume I should change both sides to match. Also I have been warned to be very carefully with the loaded spring. what to you advise for the best tool and procedure? I read in Corvette Central that the back spring should have a bow. Mine is pretty straight with car weigh on it. They make a few types? How do you recommend checking rear spring and what type is best for a good restored driver? It seems to me if I use a good tool and follow directions I can change coil spring without hurting myself even though I never did it before. Does that sound reasonable?Comment
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Re: Coil Springs
If your Corvette has the "518" springs you should be able to to remove them with no special tools. These spings are or were the only ones you could buy lately that GM still stocks for Corvettes. I put them in my 70 many years ago and didn't loose any riding height because the stock springs had taken a set and lowered the car from its as new height. The reason you can put the 518 spings in with no special tools is because they are short, but the coils are of thicker diameter and it takes a lot more pounds to compress them. I liked the way my 70 handled with them.Comment
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Re: Coil Springs
If your Corvette has the "518" springs you should be able to to remove them with no special tools. These spings are or were the only ones you could buy lately that GM still stocks for Corvettes. I put them in my 70 many years ago and didn't loose any riding height because the stock springs had taken a set and lowered the car from its as new height. The reason you can put the 518 spings in with no special tools is because they are short, but the coils are of thicker diameter and it takes a lot more pounds to compress them. I liked the way my 70 handled with them.Comment
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TerryComment
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TerryComment
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Re: Coil Springs (long)
I had a ride height issue with my 67 Camaro and ultimately chose the "remove and cut the spring" approach. I wasn't really sure what to buy so this seemed like a reasonable way to go. It worked out for me but it is a real risk. the car was 1 1/2" high in the front so I chose to cut 1/2 of the top coil which amounted to 5/8" to 3/4" of free spring height. Believe it or not the car dropped the full 1 1/2" in ride height. I thought I was being conservative and would have to do it a second time as a trial and error. The good news is I only did it once. The moral of the story is a little taken off the spring has a large effect on the ride height. Good LuckComment
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Re: Coil Springs (long)
I had a ride height issue with my 67 Camaro and ultimately chose the "remove and cut the spring" approach. I wasn't really sure what to buy so this seemed like a reasonable way to go. It worked out for me but it is a real risk. the car was 1 1/2" high in the front so I chose to cut 1/2 of the top coil which amounted to 5/8" to 3/4" of free spring height. Believe it or not the car dropped the full 1 1/2" in ride height. I thought I was being conservative and would have to do it a second time as a trial and error. The good news is I only did it once. The moral of the story is a little taken off the spring has a large effect on the ride height. Good LuckComment
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Cutting Coil Springs *TL*
Thanks for sharing your experience Dave.
If one considers that the spring is at about the half way point of the lower control arm (one should measure the relative distances more accurately than my estimate) then cutting 1/2-inch off the free height of the spring should result in one inch change in the ride height. Unfortunately, it is not that simple because free height and compressed height are just not proportional. Making the total length of the wire shorter makes the spring stiffer, so the act of cutting the spring will alter the amount the spring will compress under a given load.
While I have no personal experience cutting a coil spring, those who have advise using an air driven cutting wheel with some type of heat sink on the spring end of the coil. One person used several locking pliers and another wet cloths. They advise against using a gas cutting torch. I would think a plasma cutter would be ideal, but they are less commonly available than the cutting wheel.
TerryComment
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Cutting Coil Springs *TL*
Thanks for sharing your experience Dave.
If one considers that the spring is at about the half way point of the lower control arm (one should measure the relative distances more accurately than my estimate) then cutting 1/2-inch off the free height of the spring should result in one inch change in the ride height. Unfortunately, it is not that simple because free height and compressed height are just not proportional. Making the total length of the wire shorter makes the spring stiffer, so the act of cutting the spring will alter the amount the spring will compress under a given load.
While I have no personal experience cutting a coil spring, those who have advise using an air driven cutting wheel with some type of heat sink on the spring end of the coil. One person used several locking pliers and another wet cloths. They advise against using a gas cutting torch. I would think a plasma cutter would be ideal, but they are less commonly available than the cutting wheel.
TerryComment
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Re: Cutting Coil Springs
I cut mime with a Sawzall and it was a mistake, but NEVER use a torch. I finished my cuts with a Dremel tool and should have used it all the way. The sawzall blades needed to cut 2 springs cost $20. It is unbelieveable that a hardened steel coil can eat up quality blades but they did just that. The high speed Dremel was very effectiuve and would have saved me $15.Comment
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Re: Cutting Coil Springs
I cut mime with a Sawzall and it was a mistake, but NEVER use a torch. I finished my cuts with a Dremel tool and should have used it all the way. The sawzall blades needed to cut 2 springs cost $20. It is unbelieveable that a hardened steel coil can eat up quality blades but they did just that. The high speed Dremel was very effectiuve and would have saved me $15.Comment
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