Are some springs designed to go into negative arch?

I noticed on 1st gen trucks and runners that the front springs are flat at ride height, so that means compression at flex would be in the negative arch.

The same is true for the rear of tundras. They are pretty flat at ride height and the bump stop leads me to believe that they are in negative arch when bumped.

So, I assume that this ok for the springs to do if designed for it.

The reason I ask is that I am putting 62" tundra springs on my 4runner and wondering if it is ok to plan for negative arch.

 

The rear leafs on my Taco are in negative arch with no load. Every Taco that I have seen is the same=negitive arch^

 

cool so at flex then it is definitely negative. I had always heard that negative arch will flatten springs and possibly cause breakage, but this is clearly nto the case.

 

Let us know how the Tundra spring swap works...I haven't heard/seen much in the way of using Tundra springs.

 

Yes, it's bad for a LIFTspring to negatively arch. A spring that is designed to work in that model (negative) works fine... But take a spring with a positive arch and bend it beyond it's design limits, and you will have problems. The front AP's on my 4Runner are kind of "W" shaped in part because of this. But they are so smooth right now that I don't want to replace them.

 

These springs are a deaver set for tundras. They have a slight arch at ride height and i guess are designed to allow for negative arch, since this is how tundras work stock, from what I understand.

 

I used to do this to my Alcans:



Didn't seem to bother them at all. I think having lots of thinner leaves helps with negative arch as does a lesser arched leaf and as noted some springs are made negative to start with.

 

WOWWOWOWOWOWOW!!!!!!!!!!

I don't feel so bad anymore. Mine weren't doing that yet. hahahaha

Now, you say you used to do that.....why not anymore???

 

Got some new springs (Alcans again) with another 1.5" lift and orbit-eyes. They really work well:



I do the same on my fronts (stock rear springs):



Granted, that is a pretty rare occurrence to get them into that position, but good to know they can take it if needed.

 

before i got an aal on my truck, my springs used to go negative in a W shape when loaded down with stuff.... W shaped because the spring would be flat on the overload then flex mroe downwards where there was no overload.... they still work

 

W shape sounds bad....yowzaa