Removing Leafs & Questions that go W/ Leaf Springs

TLyons90

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Apr 22, 2013
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So I am trying to wrap my head around certain suspension information and hope a few of you can shed some light for me.

First question is how an overload leaf works on the bottom of a leaf pack? I assume when more than the standard leaf pack can support, the bottom leaf of that leaf pack starts to lay down on the top of the overload and thus support it?

Second question is wondering if there is any actual differences in leaf springs on GM trucks in general of the same years? What I mean by this is on most 1500 series trucks you have 2 leafs in the leaf pack and then an overload. On 2500 series trucks you have 4 leafs in the leaf pack and then an overload. If you were to go down to 2 leafs and an overload would you technically have a little bit greater than 1500 suspension since most HD series trucks have thicker leafs?

Final question is on removing leafs. If one were to go from 4 leafs and an overload in their 2500 series truck, down to 2 leafs and no overload but in place add airbags and traction bars. Would their be any difference really in payload and such?

Hope my questions make since and if not please correct me. Thanks!
 

TLyons90

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Apr 22, 2013
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What's your end goal? Ride quality?


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Lowness...

I've called Mcgaughtys & DJM trying to see if they plan to make hangers for the 11+ trucks and they don't. So with 2" shackles already and overload leaf removed, I am low but still not quite where I would like to be. I have been told to remove the bottom leaf on the leaf pack (which is only 1/2" thick) but assume when removing that it will allow the suspension to sag a little more and there for give maybe another 1" of drop which is where I want to be. I still plan to use my truck to load some mulch in the back here and there as well as tow a small travel trailer with roughly 500lbs tongue weight. Just don't want to completely sacrifice my "truck". But more than likely I am trying to have my cake and eat it to. Just trying to get some general knowledge on the table for others eventually maybe to.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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You're thinking too hard on this

Pull the leafs, put bags on, put axle wrap bars on and drive it.

2 leafs on a 1500 leaf pack does not equal the same as going down to 2 leafs on your truck. The spring rate is different between both setups even with the same amount of leafs. You will have less preload in the leaf pack pulling leaves from your truck vs running a 1500 pack as well.

Really it's shit that not too important if you run overload bags with your springs
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
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Lowness...

I've called Mcgaughtys & DJM trying to see if they plan to make hangers for the 11+ trucks and they don't. So with 2" shackles already and overload leaf removed, I am low but still not quite where I would like to be. I have been told to remove the bottom leaf on the leaf pack (which is only 1/2" thick) but assume when removing that it will allow the suspension to sag a little more and there for give maybe another 1" of drop which is where I want to be. I still plan to use my truck to load some mulch in the back here and there as well as tow a small travel trailer with roughly 500lbs tongue weight. Just don't want to completely sacrifice my "truck". But more than likely I am trying to have my cake and eat it to. Just trying to get some general knowledge on the table for others eventually maybe to.

Can you move the factory hanger up... Anything else is going to make ride and load capacity suffer, or not be as good as factory.
 

TLyons90

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Apr 22, 2013
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You're thinking too hard on this

Pull the leafs, put bags on, put axle wrap bars on and drive it.

2 leafs on a 1500 leaf pack does not equal the same as going down to 2 leafs on your truck. The spring rate is different between both setups even with the same amount of leafs. You will have less preload in the leaf pack pulling leaves from your truck vs running a 1500 pack as well.

Really it's shit that not too important if you run overload bags with your springs

Was hoping you would chime in!

I like your thoughts of just go for it! My thoughts to were if your running bags and bars it's about the same. I also figured spring rates and such were different, just wasn't 100% sure. It all sounded good in my head.

What exactly do you mean by less preload?

Can you move the factory hanger up... Anything else is going to make ride and load capacity suffer, or not be as good as factory.

Unfortunately in my eyes it does not look possible. Especially when you look at a pre 11 truck and its design. It looks to me that with the 11+ trucks and being a 3" wide leaf that the 1/2" difference actually goes under the frame. So if you were to lift it, it would contact the frame and or be cockeyed.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Was hoping you would chime in!



I like your thoughts of just go for it! My thoughts to were if your running bags and bars it's about the same. I also figured spring rates and such were different, just wasn't 100% sure. It all sounded good in my head.



What exactly do you mean by less preload?







Unfortunately in my eyes it does not look possible. Especially when you look at a pre 11 truck and its design. It looks to me that with the 11+ trucks and being a 3" wide leaf that the 1/2" difference actually goes under the frame. So if you were to lift it, it would contact the frame and or be cockeyed.



Preload is the amount of "spring" under potential energy while truck is stationary. It makes the difference in how the axle and tires and pressed back to earth when you hit a bump and the tires fly up. Gravity only does so much as well as shock valving.

People think you must have a ton of tension or "preload" in the springs on stock leafs at ride height but it's not so. There aren't enough leafs in the pack to create a nice linear spring rate that increases through out the suspension cycle so at one point, you will hit max spring rate but the springs will continue to bend. When you go too far into this, that's when springs loose their capacity, break or fall flat instead of keeping an arc.

Lots of science into a good working leaf spring. Look at a desert truck with rear leafs. It will have 15-20 leafs in it but will be much softer than a 2500hd leaf pack. This is done to create preload and increase spring rate through 20" of spring travel to make everything work correctly. They generally will be pulled apart and inspected every race to every other race making sure arc is still good and leafs are not cracked or broke.
 

TLyons90

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Apr 22, 2013
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Preload is the amount of "spring" under potential energy while truck is stationary. It makes the difference in how the axle and tires and pressed back to earth when you hit a bump and the tires fly up. Gravity only does so much as well as shock valving.

People think you must have a ton of tension or "preload" in the springs on stock leafs at ride height but it's not so. There aren't enough leafs in the pack to create a nice linear spring rate that increases through out the suspension cycle so at one point, you will hit max spring rate but the springs will continue to bend. When you go too far into this, that's when springs loose their capacity, break or fall flat instead of keeping an arc.

Lots of science into a good working leaf spring. Look at a desert truck with rear leafs. It will have 15-20 leafs in it but will be much softer than a 2500hd leaf pack. This is done to create preload and increase spring rate through 20" of spring travel to make everything work correctly. They generally will be pulled apart and inspected every race to every other race making sure arc is still good and leafs are not cracked or broke.

Ahh ok, that makes since. Thanks for clearing that up!