Thoughts on rearching front spring

[JayJay]

I re-arched my front spring using a much less precise method than Brent, but in the end it was effective. First, determine that your spring needs to be re-arched. The eye center-to-eye center measurement should be 30-5/8" to 30-13/16", and the arch should be 4-7/8" to 5-1/8" from the bottom of the spring leaf to the table when the spring is resting on its eyes. These numbers are published in a number of places, but I used this document that appears to be pretty well accepted (I don't know who wrote it or when it was written, but it's pretty comprehensive).

I followed the directions in the document for hand arching the springs. I used a Sharpie to put tick marks on the underside of the spring, and then clamped the leaf in a big bench vise with the tick mark at the top of the jaws. I used a couple of pieces of 1/4" steel to avoid getting vise jaw marks on the leaves. I then put a big crescent wrench on the end of the leaf and leaned on the wrench until the back of my workbench lifted up (I told you this was crude!). Rinse and repeat. I did not bother to re-arch the top (short, with the square hole) leaf. I measured the arch of each leaf before and after, I got anywhere from about 1/8" to 3/8" on each leaf I worked on.

When I put the spring back together it was actually a bit over-arched, but I think that will even out in use.

I tried the same on the rear spring but the leaf material is so much thicker that it only was effective on the longest of the leaves.

All the spring leaves needed to have their lower surfaces relieved at the tips to get rid of the sharp sheared edge. In addition, quite a few had trenches dug into their top surfaces from the aforementioned sharp edges, and I ground those lips down. I did this all before I re-arched.

I painted the bottom of the bottom leaf and the top of the top leaf with enamel, and then all the rest of the leaves with graphite paint.

In hindsight, it would have been nice to have the sweeps to be able to verify that each leaf was where it should be. I found a local company that would have hot-arched to original sweeps, but since I didn't have that data I decided to do it the way I described above.

[alexiskai]

Originally Posted by JayJay

I re-arched my front spring using a much less precise method than Brent, but in the end it was effective. First, determine that your spring needs to be re-arched. The eye center-to-eye center measurement should be 30-5/8" to 30-13/16", and the arch should be 4-7/8" to 5-1/8" from the bottom of the spring leaf to the table when the spring is resting on its eyes. These numbers are published in a number of places, but I used this document that appears to be pretty well accepted (I don't know who wrote it or when it was written, but it's pretty comprehensive).

I recently watched a video by a fellow who followed this procedure. It's a two-part video – in part 1 you see him arc the leaves and in part 2 he re-assembles. Long story short, it's ineffective. He gets a higher arc on paper but the car sits the same as it did before he started.

I think it's hard to use this method, in part because the force is applied crudely and it's easy to underestimate how hard to pull, and in part because most guys won't have a known-good reference arc to aim at.

https://www.youtube.com/watch?v=VpGXCdKo05w