Recurved leaf springs

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gerahead

gerahead

Glutton for Punishment
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I need to replace the rear leaves on my 71 Dart. It was originally a 318, but I am replacing it with a 340. The originals are flat as a board (PO had shackles bolted through the frame that are about 6" long! I am thinking about getting the old ones recurved since they are the originals. Anyone here ever recurve theirs? How did it work out for you? Thanks! L8r

Jim
 
I am wondering the same thing, have the same type of situation with my leaves.
 
Re arcing the spring will not affect the free spring rate. It will affect the installed rate. So the car will sit higher but the spring will still be worn out. Buy new springs.
 
I sorta cheated but it worked well on mine. I don't care much about drag "launch" but I wanted stiffer anyhow. I realize not all have this option

I took the original pack apart, and another set off a later "A" and used the longest leafs. In other words, (on each side) 1 "eye" leaf for the mount, 2X longest, 2x next longest and so on, until I had the same leaf count +1 as I recall. This stiffened it right up and raised it some too I bought spring clips and longer U bolts from the spring outfit in Spokane, Pohl Spring

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I've rearched many sets. The way to do it is cold. Some insist on heating with a torch and rearching. When that's done, they don't stay rearched for very long. Rearching cold and they stay arched almost as long as they did the first time.
 
TT5.9mag said:
Re arcing the spring will not affect the free spring rate. It will affect the installed rate. So the car will sit higher but the spring will still be worn out. Buy new springs.
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You'd be surprised. Rearching cold and they last quite a long time. It has to be done correctly, though. I have a pair I need to rearch. I may do a how to on it.
 
So there's two ways to do this. The first and most common is a cold re-camber. This is where the spring pack is bent into the desired shape. If the bushings, leaf liners, etc aren't replaced you'll just have worn out springs bent to ride higher. The better way involves disassembling the spring pack, annealing the steel, re-cambering each leaf individually and then heat treating (tempering) before reassembly with new bushings, liners, clamps and hardware. This will give you basically new springs, but will probably cost as much or more then new replacements. Check with your local spring shop and see what they propose and compare costs.
 
The best method is using a large oven to heat the spring to the right temp before re-aching. Cold re-aching doesn't last 30 years like furnace re-arching. The springs were originally arched in a large furnace, that's why they last so long.
 
Recurving springs is a band aid fix. Lipstick on a pig! IMO
Replace them with new. I replaced mine 17 years ago with a set from ESPO. I mistakenly bought a 5 leaf set and not a 6 leaf set like the car came with. Well there's taller tires on it but they have held up well after many years.

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The question is whether they need it. My guess is yes, but that would be because of loss of rate (overloaded and cycling). Factory springs (except SS) are designed to be flat when loaded. So with full tank and and say 100 pounds of tools or luggage in the trunk, flat would be correct. When removed, they both should have the same arch, and you can also measure the free hieght and how much the move when loaded. Used the way the OP described by guess is they will not be the same free arch...
 
I took mine to a spring shop 4 years ago & they replaced the main leaf. Still sits very nice!
 
I have used many sets of recurved springs on the last 50 years on cars and heavy trucks.

They work...
 
The previous, previous owner installed ManciniRacing 2800lb leaf springs on my '71 Dart GT (over 19 years ago). My car has the factory installed sbp 8 3/4" rear end (3.23:1 sure-grip 741). The rear wheels are (WheelVintiques) 15" X 7" Rallye wheels with P245/60R15 tires (could have gone with P255/60R15s). The front wheels are (factory) 14" X 5 1/2" Rallye wheels with P195/75R14 tires.

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toolmanmike said:
Recurving springs is a band aid fix. Lipstick on a pig! IMO
Replace them with new. I replaced mine 17 years ago with a set from ESPO. I mistakenly bought a 5 leaf set and not a 6 leaf set like the car came with. Well there's taller tires on it but they have held up well after many years.

View attachment 1715962737
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Mike, have you ever done it? Just asking.
 
RustyRatRod said:
And here I thought we were talking about leaf springs.
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Lmao. Setting at the Mex restatunt with the family enjoying margaritas. I got sidetracked with posts. Ask me about typeF. LMAO
 
here is my wrecking yard specials for a 67 polara 500 to my 69 dart , just added a few and replaced the center bolts .

DSC07070.JPG
 
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