[4.3L XJ]

OK, now for my 2 cents. First I will tell you that I used to design and build lift kits from scratch in the 70s, until Rancho put me out of business with Chinese stuff. I have also worked briefly in a spring foundry. So here it is.

I see two things wrong here. First the middle of the spring is not supported enough and all the bending is there. Eventually, this spring will sag as it will loose the temper there from being bent too far.

Second, I am going to trash some internet conventional wisdom. It is a popular thing to put the shackle at the angle you have there, and you obviously bought a kit for that purpose. However the reason they soften the ride is that they make the spring bend exactly as you have shown here (Thanks for the pics on this). The spring bends in an unnatural way and only bends on one spot instead of all over so the ride is "softened". Now I can find probably a hundred guys on forums that will disagree with me on this, but the proof is in the pics.

 

[4.3L XJ]

I would need to see a little better pic of the center of the spring, but the addition of a short leaf might solve the problem

 

[4.3L XJ]

Yup I think so too. This just means they use an adjustable table that doesn't have a good center adjustment. However I still stand by having a shorter leaf added to the center. That bottom leaf is too long IMO

 

[4.3L XJ]

What I would do, is instead of adding a curved leaf, which would stiffen your ride considerably I think, is use a flat tapered leaf about the length of the last leaf, then remove it and use the flat one. This would give you a two stage spring that should have a ride about like what you have now and the center would be supported

 

[4.3L XJ]

Any chance you would have a link of what you’re referring to? All I seem to find are curved add a leafs.

And what would be the long term theory of what would happen by running springs like this without adding anything?


Edit:
This is what IRO would have me use to add to my pack:

IRO 3.5" Leaf Spring Add-A-Leaf - Iron Rock Off Road

Sent from my iPhone using Tapatalk

The best place to get that leaf would be at a pick and pull. There are tons of them on rear springs in a wrecking yard, and they would be cheap. One off an S10 would be ideal and if you were local to me, I probably have some sitting in the scrap pile

 

[4.3L XJ]

You got it.

 

[4.3L XJ]

Good point Gluck. What you refered to is called snap. Usually, there is only about 1/8" snap between leaves in a pack. I use a couple of C clamps when I do it. Also you will need a new center bolt. Make sure they are real center bolts. They are soft and made for the purpose. Using something like grade 8 hardware for this will insure the bolt will brake at some point

 

[4.3L XJ]

👍👍👍

 

[4.3L XJ]

You have a fundamentally different spring here. This is a two stage spring as opposed to a single stage spring. They ride better, but can still support the weight as the bottom leaves come into play. I run a bastard pack that is set up like this and works well for me

 

[4.3L XJ]

It is hard to tell okn a two stage spring. The mathematics are much more complicated. You have to start doing calculus for that

 

[4.3L XJ]

Sounds good. Those two stage springs always ride better

 

[4.3L XJ]

Never broke my locked 30 either, but like Quick I have other axles ready to go. Shoot, I never have broken my locked D35 either, but that doesn't mean it can't be done from a lapse in judgement