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Old 05-24-2021, 11:27 AM   #1
Standing Elk
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Default Re arc front spring

Has anyone had their front spring re arced as opposed to just replacing it? Thanks
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Old 05-24-2021, 11:44 AM   #2
BRENT in 10-uh-C
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Default Re: Re arc front spring

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Originally Posted by Standing Elk View Post
Has anyone had their front spring re arced as opposed to just replacing it? Thanks
We do it on almost every front spring now. We made sweeps to make each leaf to the correct contour. We have a fixture that is basically two pieces of round bar stock that we use in the press to support the leaf. Then gently radius the leaf as we move it along. Most leaves do not need any more than a couple of light presses to put them back into the correct shape. I will see if I can add a picture or two of the sweeps and holding fixture.
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Last edited by BRENT in 10-uh-C; 05-24-2021 at 11:54 AM.
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Old 05-24-2021, 11:54 AM   #3
Standing Elk
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Default Re: Re arc front spring

Thanks Brent. I am curious how you deturmin what the correct radius for each leaf is. Is there some specs. from Ford? Would also really appreciate the pictures. Another question, have you ever had any heated, retempered and re arced by a spring company. I have had the main springs on cats done that way. Would the springs tend to stay within spec better if they were re tempered? Thanks
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Old 05-24-2021, 11:59 AM   #4
BRENT in 10-uh-C
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Default Re: Re arc front spring

I actually have all of the engineering prints from Ford which gives the radius arc. We drew it up in Solidworks and then used a CNC Plasma to cut it out of sheetmetal.

We generally grind a slight bevel into each end of the #1 - #9 leaf so the will glide better on the leaf below them. We don’t use heat (-just bend them cold).
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Old 05-24-2021, 12:04 PM   #5
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Default Re: Re arc front spring

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Would the springs tend to stay within spec better if they were re tempered? Thanks

I doubt it. I guess I look at it this way. Most leaves have held up the load for about 90 years. If I can re-arch them where they only will last 1/2 of that 90 years, likely in the next 40-45 years, the front end will need to be rebuilt again, and so someone can re-arc them again at that time.
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Old 05-24-2021, 12:16 PM   #6
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Default Re: Re arc front spring

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Old 05-24-2021, 01:01 PM   #7
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Default Re: Re arc front spring

Do you over bend them a bit and then un bend them a bit to get the right residual stress in the surfaces?
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Old 05-24-2021, 02:32 PM   #8
BRENT in 10-uh-C
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Default Re: Re arc front spring

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Do you over bend them a bit and then un bend them a bit to get the right residual stress in the surfaces?
No not really. We set radius of the #1 spring to a radius of 19⅝" and then compare the ℄ measurement from eye-to-eye on the factory print and see if comes up to about 32¹⁵⁄₁₆". That is the developed length. Once all of the springs are re-arched and installed, the ℄ measurement from eye-to-eye should be about 30¾".

Another aspect that many miss (-including the repros I have seen) is under the tips of the #2 - #10 leaf, you should be able to insert a 0.015" thick feeler gage underneath the tip from ⅛" to ⅜" according to the print. We do 'fudge' a tad on this if the leaf has wear, but this is one main reason why the paint never scrapes off of the spring during normal driving.
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Old 05-27-2021, 02:52 PM   #9
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Default Re: Re arc front spring

Great information Brent, thanks.
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Old 05-27-2021, 07:00 PM   #10
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Default Re: Re arc front spring

Brent, IT has always been my experience that a spring re arced cold will not hold its shape for long. How do yours hold up after a few years of pounding in a car?
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