Tech Question - Reusing Old Leaves

Q -Mike;

I have a pair of your 2" lowering coils for the front of my 65 Falcon Sedan Delivery. Now after 3000 miles (Back to 50's & Iola) the rear passenger side is sagging 1 1/2 Inches compared to the drivers side, and the passenger front is 1/2" lower than the driver's.

When putting the Granada rear end in I added 1 leaf from my original Sedan Delivery to give it a little more stiffness. This leaf was the original leaf set next to the main. Last week I disassembled and rebuilt the passenger side and added a mid leaf from a 64 Comet 4 door sedan, to get even more stiffness and I thought a little more rake. Ditto for the driver's side.

Reassembled and set the car back down and it did not change in level at all! The main leafs were intact, the shackles seem OK, and there were no broken leaves.

I believe the car sat outside in the elements as the roof rail was rusted through as were the floor pans and the wheel houses but the 6 cyl rear axle showed no indication of being water damaged, and it made no noise upon driving it, brakes worked fine, etc. I built in a new superstructure - torque tubes tied together, all set up level and the body has never been damaged other than by rust.

The QUESTION: Why is it sagging after the rebuild? Do I need entirely new leafs. Did I use weak leaves? I would like a firmer ride and about a 3" rake for carry extra weight. It drove/drives fine, just sits crooked. What is wrong and how do I correct it. - Mike, Prescott, WI

A - Mike,

Without seeing the spring and the leaves you put into them I can not speak to their condition, but if they looked anything like these, scrap the spring.

Now if the frame was not damaged by rust and the springs do not look as bad as the above pictures the springs may still be the culprit.

The springs may have been weak from the start. Even just being less rusted then the right side picture can weaken a spring. The dark spots you see in the picture is fatigue. When the leaf is shot blasted tiny little pits will be revealed. Also lines, very much like those in the palm of your hand may also be revealed. These pits and lines are signs of the leaf fatiguing, that is the leaf is failing. It is a waste of time and effort to use any leaf which looks like this.

As for the spring on the left, these make wonderful door stops and boat anchors.

Then there is the adding the extra leaf issue. There is nothing wrong with adding extra leaves provided they are the proper size, thickness and length, and are fitted into the proper location.

The extra leaf cannot be thicker than the leaf above it and cannot be thinner than the leaf below it.

The distance between the end of each leaf is called "stepping". In order for a spring to act like a spring, that is, hold weight and deflect under load, this stepping must be maintained. Ideally the distance between the each leaf is equal for each leaf. In reality it can vary somewhat. The somewhat measurement is the trick.

If you put a leaf under the main leaf, the one with the eyes, and the end of the new leaf ended at the center line of the eyes, great. If the extra leaf is put below the second leaf it should split the difference between the ends of the leaf above it and the leaf below it. Do not add 2 extra leaves between the existing leaves. Do not add a leaf which is equally as long as the one next to it.

If it ain't stepped right, it ain't gonna work.

I think new springs are the answer. As for the rake, if it is just to carry extra weight you want to consider our Rod Ride Plus Rubber Helper Springs. They are designed to carry extra weight without allowing the vehicle to sag and provide the sweet ride you like.

To learn more about spring tech info, check out our Spring Tech 101 booklet. - Mike

PS. wonderful question, t-shirts are on the way.