Rear springs - I need 2 inches (1 Viewer)

[Tim71FJ40]

I'm putting 35s on my 71 FJ40. The rear currently sits lower than the front. Can I re-arch the rear springs to gain 2 inches?

I'm on a budget and can't pay $1000 for a full lift kit.

Any other ideas?

 

[ryanwk628]

As the radius gets smaller the arc length will stay the same and the chord distance (eye to eye) will thus get smaller. This will impact your shackle angles because the fixed eye wont move, the pivoting eye will come towards it (like my Rough Country lift I intent to replace). I would look into longer shackles and/or adding a leaf before re-curving.

This image is on its side relitave to a spring but line AB is the eye to eye. The arc through ACB would be the longest spring leaf. If you want to increase the distance between DC 2" you would need to make the arc on a smaller circle (re-curving or decreasing OD.) The byproduct will be that AB decreases you an amount you can calculate.

 

[S4Cruiser]

Depending on the springs you have on there now, you could add another leaf, swap out a leaf from another set to get the ride height you want if the sagging is weight dependent.

 

[Tim71FJ40]

So I understand rearching the springs will change the shackle angle, but is that a problem? I have long shackles on it now from CCOT

 

[thebigredrocker]

What's the bolt-to-bolt measurement of your rear CCOT shackles?

 

[ryanwk628]

View attachment 1392370 So I understand rearching the springs will change the shackle angle, but is that a problem? I have long shackles on it now from CCOT

It will work but vector mechanics says that more of the force will be imparted through the shackle into your frame rather than tangent to the shackle swing allowing your spring to flatten and absorb the impact. Ask me how I know.

Rough Country Rear Shackle Angle

• ryanwk628
• Oct 17, 2016

Rough Country lift from PO rear shackle angle