Weight placement and leverage

Fifty

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Does anyone know a formula or preferably a rough estimate formula for weight leverage?

I’m trying to figure out, (before scales since I don’t have access to any until I find someone with them), if I put weight behind the rear axle, what kind of weight jacking will it have on the front wheels if any?

So if I shove two spares behind the rear axle, as far back as they can get, yet sadly still above the rear leaf spring hangers... will it leverage any weight off the front? And if so, what’s the amount?
I need to find the wheel base... that I know. Weight of truck... weight of spares (and guess rack weight)... measure how far the contact point of the spares are behind the axle...

I’m also planning on a winch Mount in the old spare location under the bed. So that’s another chunk of weight.

But then what’s the math?

It’s late and I’m tired. I wonder if it’s even worth calculating?
 

Fifty

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Never mind. I did the math. I think it will be about 65 to 75 lbs off the front end. So 35-38 lbs of each wheel...

Not sure that will even come close to effecting spring rate on a 4600# loaded vehicle
 

Bert is my name

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I think it is safe to assume that if you were in between spring rates that moving weight off the front could mean the difference between a truck that is works good and one that works great. But without scales I think it would be difficult to verify what changes had the greatest effect. Lot of trial and error.
 

Fifty

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Yeah. I am between a 550# and a 687# spring.

I thought I found a #600 spring but it ended up being stupid stiff, it is long and at preload it ended up being equivelant to about 900-1000#

550 is too soft, 687 too stiff. I’ve gone back to the 550, adding hydro bumps at the moment and leveraging the tail.
128.5 inch wheel base. 4290 weight with out driver and extra gear.
 

Bert is my name

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You could possibly go to a dump or something like that to at least get a front and rear weight. When I ran a small fleet I used to have to verify the weight of some of the trucks for registration. I can't remember the name of the place off the top of my head but it was in el cajon if that is any help .
 

Fifty

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Sadly I’m still using the stock multimatic dssv shocks. So no coil over at the moment and no aftermarket support at the moment.

I’m in norcal, Bay Area. I’m trying to find a scale up by forged off-road where they are doing a lot (ok... all) the work on the truck
 

Fifty

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Sadly the spring diameter inside and out are different.
The 2015 to current springs are all the same size. But they only use two springs
Amongst all the level trucks. The only difference is if the truck has a diesel or gas engine. The diesel trucks use a 687# spring, the gas trucks use a 550# spring. Regardless of the trucks designation (wt, z71, zr2, crewcab, single cab, short bed or long bed).
The rear leafs however are different lengths and rates between the different models. The shocks are either “non zr2” or “zr2”. But they are the same shock wether gas or diesel.

Crazy since there is such a huge difference in spring rate between the two.

The company that makes an aftermarket spring for it, a leveling spring, is twice as stiff as the diesel spring.
 

Bert is my name

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This might sound counter productive but what about adding weight to the front of the truck to get the spring rate "right" and then move tires and such around to balance the truck.
 

Fifty

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The stock spring is 3 id.
The bottom spring perch is a weird piece with a sleeve with 360 degrees of indexing notches. There are probably 30 or so notches. I need to remember if the base had a spring indexing notch (open end spring) or if it’s just the rubber isolator that has the drop notch.

But if it’s just the rubber that has the notch, then I can run a 3 inch Id 600 spring that is 15 inches long with a flat rubber isolator top and bottom.
My goal was to find a spring that if I cut the open end tails correctly, would be the right length and rate for a 14 inch 600# spring.
 
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