Leaf spring characteristics??? Model "A" Modified

Hi all.

My car is apart at the moment for a number of small fixes and a couple of bigger ones. Over the 2 years on the road my springs have settled and I'm wondering about resetting them or maybe adding a leaf to each.





Pics from my build.

I have an original A rear spring with 7 leaves in it. The front was custom made also with 7 leaves.

The car rides well but could maybe cope with being a little stiffer. And I'd like to bring it back up to its original ride height (about an inch higher).

Should I just reshape my spring leaves in my press to bring it back up or add a leaf? If I add, which leaves should I add? I remember reading somewhere about the function of each of the leaves. I only vaguely remember....long leaves for ride, short leaves for load...or something along those lines.

The car is the one in my avatar. Not sure of the weight but its a 401 nailhead and I think they are 660 lbs.

Thanks

Pete

 

I've been wondering where all you guys are. Then the penny dropped. You're all asleep with a belly full of food.

 

The short leaves are the ones that make a spring stiffer...

 

If you didn't want stiffer response, I'd be tempted to shim. Too, it does depend upon how old the rear spring is in your build. A new one might be just the ticket.

 

I don't necessarily want a stiffer ride, but I think it could handle being a little stiffer. It doesn't bottom out on anything so maybe shimming is the answer. I already have a slightly shimmed front and about a 1" spacer in the back to account for the removed leaves. Shimming could be an option.

The front spring was brand new 2 years ago, the rear one was brand new in 1928. They both settled about the same amount over 2 years so I don't know if replacing the rear one would be an advantage.

Thanks for your suggestions.

 

You can have a set of leaves re-arched I've been told.

 

I've seen guys reversing their main leaf just using a shop press and a chalk line on the shed floor. I figure I should be able to do something similar to re-arch mine. I suppose the question is then, will it just return to where it is now in the next couple of years?

 

Hard to see your rear spring accurately but I'd say took at adding a leaf in between the 2nd and 3rd existing leaves, since it looks like there is a largish step in that range.

As for the front if the shackles are still sitting at a reasonable angle just add that spacer block which I think you have under the spring on your U bolt plate to the top of your spring for now and see what you think.
That way you have done little work and raised the front without changing the ride comfort, at least until you have a chance to see how it goes.

I dont see why you would need to think about reversing eyes if the height it too low now. Reversing the rear would be a mistake in my book. If you think you want to do it just get a new main leaf made with the eyes reversed. Note when reversing spring eyes it will change eyes centers so you will need to know what center measurement and set you require. Also resetting means adjusting all leaves not just the main.

 

The shim in the front is already above the spring but I could put in another one or a bigger one.

I can certainly add a leaf between 2 and 3 in the rear.

I had no intention of reversing anything...just re-arching the leaves to get a bit more arch in them. I'm just not sure that will help in the long term. I'm guessing it would just settle again.

I think I might try your suggestions. They are easy to do so nothing lost if I don't like it.

Thanks

 

Cool, go for it, nothing ventured nothing gained...
Let us know how it works out.

 

I did some searching for more info. Found a recent thread talking about calculating spring rates etc. Probably a little too technical for me but obviously there's some knowledge on the subject on here.

Back to the top to see if we get any more info.

Pete

 

Essentially you are looking to increase the # of lbs. required/inch of deflection...i.e. stiffen a bit, a higher spring constant "K" if you will.
(apologies, my attempts at trans: Eng. speak)

 

a spring retains its shape because it is formed at a red hot tempature then cooled rapidly too heat treat them bending one while it is cold is a bad idea it could actually become brittle and break and yes the years wear them out but perhaps some better shocks would go along ways you have a very nice car it wouldnt make sense too clamp your spring in a shop press and apply pressure this is a pretty red neck method which may work but why test it on your beauty
i would attempt too add a leaf or have them tested checked and potentially changed by a pro spring shop

the height is what it is add a spring or have them rearched or put in a spacer but the looseness may come from shock wear i cant tell but they look like hydraulic in which case rebuild them or at least swap in new or thicker oil too slow down the movement