“Spring rate: Usually expressed in lbs/in, it’s the force required to compress a linear spring one inch. Linear springs have a constant spring rate. Progressive springs have progressive spring rate that rise has the spring load increase.”

Soaring,
Here is another try at it.

Driver side spring has a spring rate of 165 pounds an inch, is 52” long eyelet to eyelet (this does not matter, but it is the length of a mustang spring), under no load the spring has a 4” arch. The arch is measured from the centerline of the eyelets to the axle perch for the purpose of this example, the leaf spring has a 4”arch.

Passenger side spring looks exactly the same, except that it has a 5” arch, it is made out of the same steel, has the same amount of leafs, but was bent to a 5” arch before it was hardened. So the passenger side spring also has a spring rate of 165 pounds, and is 52” long eyelet to eyelet, but under no load has a 5” arch opposed to the 4” arch on the drivers side.

So, we bolt these springs under my 71 Mustang, and for the purpose of this example it weighs 1,485 pounds over the rear end. The way it works out in perfect math world is that the passenger side spring will deflect 5” ( with a force of 825 pounds…5” X 165 pounds) and the drivers side will deflect 4” (with a force of 660 pounds… 4” X 165 pounds), both springs will be flat, and the passenger side spring will be carrying 165 pounds more than the drivers side, just because of that additional 1” arch.

In reality the rear leafs would not share the weight perfectly, and may lean to the side a little bit, but you got to count on the much stiffer spring rates of the front end, and the front anti-sway bar to counter the small difference in the rear, so in the real world, you would end up with more weight on your right rear by using a spring with more arch, or a stiffer spring.

 

[sm=exactly.gif]
Thats exactly what I was going to say.
Good post, Bentworker...

 

Yeah Bentworker......excellent. Now I understand.

 

You can either add a helper spring or air bag spring to get a higher spring rate on the right side. This would be used only when needed. The sway bar adjustment also helps.