OBS F250 slow adventure build

[Korben]

FANTASTIC thread and build, I'm very impressed with the front end work. I've got a couple of these trucks, not as nice as yours but a good start. I've been concerned with up travel in thinking about my future front end mods, you've proven that good up travel can be done.
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Got a KISS answer for your rear stiffness/articulation. Remove or cut off that big flat bottom overload leaf that I think you still have, or find leafs with the other overload style. Ford used two overload styles on these trucks. That big thick short flat leaf that you have, or a pack without that big sucker with another leaf on top with more curve and another set of pads on the frame, I prefer the later.

 

[underdrive]

Got a KISS answer for your rear stiffness/articulation. Remove or cut off that big flat bottom overload leaf that I think you still have, or find leafs with the other overload style. Ford used two overload styles on these trucks. That big thick short flat leaf that you have, or a pack without that big sucker with another leaf on top with more curve and another set of pads on the frame, I prefer the later.

I'll have to disagree with you there. The flat bottom leaf contributes nothing towards limiting rear suspension flex, it only comes into contact with the leaves above it when said leaves are flat. Which is usually a result of the loose nut behind the wheel loading up the bed so heavy the tires are fixing to pop. Coincidentally this is also about the point where the axle touches the bump stops on the frame - with or without the leaf he won't be able to get much more up-travel there...

The other style of overloads you mention, the ones with the upper leaf (or leaves) and second set of frame brackets, now them things limit suspension flex something fierce. You only get like 2" of up-travel on the main packs till the overloads make contact with their frame brackets. From there on the spring rate ramps up significantly, which is what kills overall suspension flex. One of our 1-tons actually has multi-leaf overloads that sit a mere inch below the frame brackets - the rear axle is purposely restricted so it doesn't flex worth a hoot, as doing so would prove detrimental to the use said truck usually sees. Front axle on the other hand is pretty much allowed to float as it pleases, this is where we get the articulation for traction at all four wheels.

Also FWIW the OP's F250 should not have the upper overloads, those were usually reserved for the 1-ton trucks as they are what makes for the higher rear GAWR. The axle itself is physically identical between 3/4-ton and 1-ton SRW, it's the leaf packs and those upper overloads that allow the higher capacity for the F350s.

 

[leojr]

The other style of overloads you mention, the ones with the upper leaf (or leaves) and second set of frame brackets,

I scavenged a set of the 1 ton overload leafs. They also us a 1" spacer that sets them above the spring pack. I have the frame brackets too, but will bolt them in if/when I need them. It would be easy to fabricate a bracket that rotates down and into play when needed , and swings up and out of the way when not. I get a lot more rear spring travel with the softer SD spring.

 

[Korben]

Don't want to turn this into an argument but..
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I'll have to disagree with you there. The flat bottom leaf contributes nothing towards limiting rear suspension flex, it only comes into contact with the leaves above it when said leaves are flat. Which is usually a result of the loose nut behind the wheel loading up the bed so heavy the tires are fixing to pop. Coincidentally this is also about the point where the axle touches the bump stops on the frame - with or without the leaf he won't be able to get much more up-travel there...

Not with his shackle reversal, his springs can now go well past flat before the axle contacts the bump stops.
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The other style of overloads you mention, the ones with the upper leaf (or leaves) and second set of frame brackets, now them things limit suspension flex something fierce. You only get like 2" of up-travel on the main packs till the overloads make contact with their frame brackets. From there on the spring rate ramps up significantly, which is what kills overall suspension flex.

But that is on a stock truck, now with his shackle flip if he had the pads and that spring he'd have 6-8" between the overload spring and the pad. For him it would function more like a long travel bump stop. This however is likely moot, as amgvr4 I gather wouldn't want either overload system.
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Also FWIW the OP's F250 should not have the upper overloads, those were usually reserved for the 1-ton trucks as they are what makes for the higher rear GAWR. The axle itself is physically identical between 3/4-ton and 1-ton SRW, it's the leaf packs and those upper overloads that allow the higher capacity for the F350s.

No amgvr4 doesn't have the upper overloads, I could see that in the pics, but all the frames have the holes for mounting the pads. Also FWIW your wrong about which trucks got what, I own 6 of these trucks, 3 F250s and 3 F350s. I find no rhyme or reason as to what got what system. I'm sure there is one but it's not as simple as above or below a certain GAWR. Best example my F250LD with the SF10.25 had the over spring overloads. I took them off to put them on my F250HD, 7.3, Ex-cab, 4wd.
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[underdrive]

I scavenged a set of the 1 ton overload leafs. They also us a 1" spacer that sets them above the spring pack. I have the frame brackets too, but will bolt them in if/when I need them. It would be easy to fabricate a bracket that rotates down and into play when needed , and swings up and out of the way when not. I get a lot more rear spring travel with the softer SD spring.

Yup, them be the ones in question. Unfortunately being a single leaf and not very thick I don't think do a very good job at supporting heavy loads, like for example a camper. They are however very efficient in limiting your suspension travel when not loaded down much.

So you got the SD leaves, cool. Do you know how their codes (A, B, C, etc.) relate to axle weight rating (GAWR)?

 

[underdrive]

Don't want to turn this into an argument but..

Not gonna

Not with his shackle reversal, his springs can now go well past flat before the axle contacts the bump stops.

I was under the impression it is bad for leaf springs with relatively high positive arch to be bent the other way? Correct me if I'm wrong there...

But that is on a stock truck, now with his shackle flip if he had the pads and that spring he'd have 6-8" between the overload spring and the pad. For him it would function more like a long travel bump stop. This however is likely moot, as amgvr4 I gather wouldn't want either overload system.

Indeed. Forgot he did the rear shackle flip. Big thread, lots going on over long period of time, easy to lose track of things.

No amgvr4 doesn't have the upper overloads, I could see that in the pics, but all the frames have the holes for mounting the pads. Also FWIW your wrong about which trucks got what, I own 6 of these trucks, 3 F250s and 3 F350s. I find no rhyme or reason as to what got what system. I'm sure there is one but it's not as simple as above or below a certain GAWR. Best example my F250LD with the SF10.25 had the over spring overloads. I took them off to put them on my F250HD, 7.3, Ex-cab, 4wd.

Well that's Ford for ya. Currently I know of one F250LD with the SF Sterling that doesn't have upper or lower overloads. I know of one F250HD that also lacks uppers but has the flat fatties. I know of two F350s that have both upper and lower. I've seen many others, these are just what I've messed with fairly recently.

 

[Korben]

I was under the impression it is bad for leaf springs with relatively high positive arch to be bent the other way? Correct me if I'm wrong there...

I'm sure it's not good, but don't think of it as bad either, what choice do you have if you want a long travel leaf spring.
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Well that's Ford for ya. Currently I know of one F250LD with the SF Sterling that doesn't have upper or lower overloads. I know of one F250HD that also lacks uppers but has the flat fatties. I know of two F350s that have both upper and lower. I've seen many others, these are just what I've messed with fairly recently.

Best I can figure it's about the combination. That spring A + overload system M = Rate X. For example my F250LD is probably the same spring as a F150 plus the overloads to give it enough rating.
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[Seabass]

I was noticing that you posted on the ford full size thread. I'm curious.....is that truck your daily driver?

 

[amgvr4]

I was noticing that you posted on the ford full size thread. I'm curious.....is that truck your daily driver?

Why yes it is! I do everything with this beast including drive it every day. That is a big reason I have made all the more specialized parts of the truck removable if need be. Depending on what I am doing I can remove the bed rack and tire carrier to make it a little more utilitarian. There was one week in July when I took the family on a 600 mile road/camping trip, towed my little brothers ranger on my 18' trailer, and went wheeling up to Gallagher Head lake. That's pretty good for a 19 year old, 263,000 mile work truck! It also gets 17.5 mpg loaded for a family trip or driving to work.

 

[Seabass]

I thought you did. I too use my truck in the same way. Sort of.... I do have my old gasser that's pounded on the farm every day. It's good, but I'd rather not get real far from home in it. But my old power stroke is my go-too. I pulled my 18' camper just over 600 miles back in July to get to Charleston SC. Then 600 back home. I find it satisfies me in a good way to run a nearly 20 year old truck with 35" mud grips, a winch, some lift, and ton of recovery gear for my "best" vehicle. My truck looks and feels more at home on the trail than the highway. As does yours. I remembered early in your thread that you drove it daily, I was just curious if you still did. A lot of guys end up getting a car or something else to drive and use their rigs only when camping. I'm glad to know I'm not the only person counting on their camping rig to get groceries. You've done a fine job too! I really like the short bed on your truck. I don't see as many of those. Mines as long as a bus! But, for my lifestyle I need a long bed. But I bet that extra two feet you don't have makes it a LOT nicer in the tight spots.

 

[leojr]

So you got the SD leaves, cool. Do you know how their codes (A, B, C, etc.) relate to axle weight rating (GAWR)?

From notes I've gathered elsewhere, below are the listed ratings, please don't take as gospel. I also do not know how this is calculated or representative of. These are for '99 SD models.

I selected the B code SD rear leafs. What I do know is that I can bounce the truck bed standing on the bumper with these springs and I could get zero movement with the stock springs. Similar experience with my front SD springs too.

A (found on SD F250 and Excursions) 6,084lbs
B (found on SD F350 SRW) 6,830lbs
C (found on SD F350 DRW) 8,250lbs

 

[CYRUS888]

This is an awesome build man!!!!:Wow1:
I'm planning on upgrading my suspension and came across your build
For now, I got a BDS 4 link kit. It flexes ok but not great
I should have built my own suspension right off the start
My plan is to do a radius/Y link up front like yours and parallel 4 link in the rear but instead of using coils I'm going for air bags all around just for height adjustability and manipulating air pressure on every corner to move the COG to where I want it especially in trails.
Can't wait to see what you come out with for links in the rear:coffeedrink:

Here's how my truck flexes as of now...

 

[amgvr4]

Your SD looks good man. I have never looked into air bags for long travel. Do they make some with enough stroke to get good articulation? It would be nice to be able to vary the spring rate and ride hight at any point in time.

 

[CYRUS888]

Thank you. Your truck looks amazing too and performs even better than some apparent "trail rated" vehicles. Awesome build so far man!!!

So far i found this airbag
http://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=8628
Ive contacted them to see if there is anything with better specs than that. Waiting for their reply back. I'll keep you updated with what they say.

My plan was using Airock control unit with the air bags
http://www.offroadonly.com
Airock is an amazing product. Its geared towards jeeps but I've talked to them and they said they can work with me to make it work on my truck. Airock has a sway bar that can be controlled by the control unit(also has a manual version). If your vehicle reaches a certain speed the control unit will automatically lock your sway bar and bring your air bag hight to your set on road height. The control unit will keep your truck levelled at all times which helps with off cambered situations and you could move your body into positions where you want it via in cab touch pad. Im not a sales rep for these guys by any means, I've just been impressed with what I've read so far from people that has this in their rigs.

Hope that helps shed a different perspective to suspension that your usual coil overs especially with you dealing with either your suspension is too hard or its too soft

 

[Korben]

There's air bags out there made to replace one or both of the springs in your coil-overs.