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Discussion Starter #1
Hi all, I am looking at replacing the rear springs in my 94 f350 with rear springs out of a 97 f250 hd springs, after o removed the 97 springs I noticed the 97 only has 3 leaves and the 94 has 5 leaves, are they the same spring rate with just less springs or are these 2 different spring rates?
 

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F350 vs F250. You should be fine as my F250 rarely squats when loaded with anything heavy. Put a good set of shocks on it too.
 

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There are a few different sets of springs for these trucks.

I just went through all this dealing with ATS with the springs on my ‘96 250. Which is gvwr 8600. This one has 5 leafs, 10.25 rear, D50 front. There were also 4 leafs for a lot of 250’s. If you haven’t owned them since new, they could have been changed out at some time. My front ones have been, they have 3leafs. We don’t know what is in there.

There are also various options of HD aftermarket springs and rates. I’ve been looking at going with heavier springs on mine.

In all honesty, I did a lot of research into the various springs and rates, and gave up trying to figure it out for these trucks. Even my local spring shop got lost in it. I went with ATS, the guy I’ve been dealing with has been Johnny on the spot and knows his stuff.

There could be a big difference between 250’s and 350’s in their rates. In my personal experience a 3/4 ton won’t take anywhere near the weight a one ton will.

You might want to get in touch with ATS and see if they can help you out.
 

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Discussion Starter #4
My 94 has overload springs also as where the 97 doesnt but those will be transferred over with the other springs so I will retain the overloads. That's the reason for swapping springs is because the overloads are thin where they rest on the stops so I know the truck has carried heavy loads a majority of its life and this way I can replace the bushings without having the truck down for any amount of time.

Not really sure what shocks would have to do with the squatting of the truck??
 

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Discussion Starter #5
There are a few different sets of springs for these trucks.

I just went through all this dealing with ATS with the springs on my ‘96 250. Which is gvwr 8600. This one has 5 leafs, 10.25 rear, D50 front. There were also 4 leafs for a lot of 250’s. If you haven’t owned them since new, they could have been changed out at some time. My front ones have been, they have 3leafs. We don’t know what is in there.

There are also various options of HD aftermarket springs and rates. I’ve been looking at going with heavier springs on mine.

In all honesty, I did a lot of research into the various springs and rates, and gave up trying to figure it out for these trucks. Even my local spring shop got lost in it. I went with ATS, the guy I’ve been dealing with has been Johnny on the spot and knows his stuff.

There could be a big difference between 250’s and 350’s in their rates. In my personal experience a 3/4 ton won’t take anywhere near the weight a one ton will.

You might want to get in touch with ATS and see if they can help you out.

I plan to add air springs as helpers but hook up a leveling system like a semi truck uses to always maintain a proper ride height while loaded or unloaded just like a semi truck and that was it will adjust everything on it's own instead of me having switches inside the cab and always making corrections to the bags.

But by the looks of things I'll probably just install the poly bushings into my stock springs and call it good.
 

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I plan to add air springs as helpers but hook up a leveling system like a semi truck uses to always maintain a proper ride height while loaded or unloaded just like a semi truck and that was it will adjust everything on it's own instead of me having switches inside the cab and always making corrections to the bags.

But by the looks of things I'll probably just install the poly bushings into my stock springs and call it good.
Not to detract from your plan, or be negative, but I always wonder about transferring the loads around. Instead of the loads energy being dispersed into the frame through the springs, it gets directed right to the axel etc on air bags. I’m not an engineer, I have no idea if it really affects it or not. I’ve just always wondered about all those types of systems. I’ve never used them, if my one ton trucks couldnt handle the weight, I called in a Kenworth! But, that’s just me. Lots and lots of people use them for years.

I’d be curious what you find out about the 3 leaf springs.
 

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Discussion Starter #10
I'm going to do it to maintain proper ride height, when the truck squats from being loaded its altering the steering geometry that was preset from the factory, not so.much to carry more weight.
 

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the newest Earthroamer 550 uses all airbags to hold it up = no leafs

some Dodge pick ups uses coil rear and it lands center frame over axle

I run 7000 lbs bags ( over axle to center frame and can have as much as 5000 lbs of weight in the bed with no issues
I imagine there is still a lot of the weight distributed thru the leaf springs and frame mounds even with the bags aired up
they are helping and not taking the load ( IE if you removed the springs and just had the standard air bags
the truck would not sit at the same level with just the bags)


I look for stress cracks on a regular basis but these trucks do not seem to break in half like the Dodges do ;-)
 
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