How good can a full-size solid axle suspension be?
- Thread starter Metcalf
- Start date
Metcalf
Expedition Leader
Nothing heavy enough to make up the difference in weight.
Metcalf
Expedition Leader
Keeping the front end as light as practical isn't a bad thing.
Food for thought, replacement coil bucket may be useful, modifiable, or inspirational....
autofab.com
Coil Buckets with Spring Adjusters - Autofab
Custom-made coil spring pockets or buckets featuring the Autofab coil spring adjuster assembly. These buckets allow for an external shock mounting structure for long travel shock locations. Adjuster kits allow for fine-tuning the ride height and to restore alignment after the coil takes a set.
autofab.com
PMF 2005-22 SD OEM Replacement Fabricated Buckets-PMF-BRK100
www.pmfsuspension.com
Metcalf
Expedition Leader
Food for thought, replacement coil bucket may be useful, modifiable, or inspirational....
Coil Buckets with Spring Adjusters - Autofab
Custom-made coil spring pockets or buckets featuring the Autofab coil spring adjuster assembly. These buckets allow for an external shock mounting structure for long travel shock locations. Adjuster kits allow for fine-tuning the ride height and to restore alignment after the coil takes a set.
PMF 2005-22 SD OEM Replacement Fabricated Buckets-PMF-BRK100
www.pmfsuspension.com
Yup, I have been looking pretty hard at this one from Carli. It converts the upper shock mount to an eye style and allows packaging a 2" longer, up to 3.0 diameter, shock.
luthj
Engineer In Residence
If you could bolt in a 2.5 with a standard coil profile, that would be worthwhile. The ability to use off the shelf springs, would be worth it I think.
Would your travel be limited significantly? If you can still get at least 4" in bump, I don't think its going to impact the ride quality much, at least on actual roads.
Would your travel be limited significantly? If you can still get at least 4" in bump, I don't think its going to impact the ride quality much, at least on actual roads.
CodyY
Explorer
You're currently at stock ride height now, correct?
What's the axle centerline to fender distance?
I'll go measure mine is a sec
Edit: 28" and 8" from bottom of frame to bumpstop pad on the axle
(Carli 2.5 pintop and carli "diesel" springs
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Metcalf
Expedition Leader
There are no off the shelf 05+ springs that seem to do what I want. Generally everything seems to be made for diesels, or marketed as fitting both ( which is just as bad ). You also can't find any real data on what the springs are you would be buying.....spring rate seems to all of a sudden be a top secret thing? The most you can get out of most companies is that they are 'softer' or maybe they are 'linear' or 'dual' rate. I find the lack of actual tech information really frustrating.
I am trying to preserve all the factory up-travel without needing to lower the bumpstop. Depending on how much the factory bumpstop is actually going to compress, it would give me just about 4" of uptravel. If I can lift the front of the truck about 1-1.5" that should let me have 5" of uptravel. From personal experience, I think that is a good minimum. With the Carli tower it looks like I can package just about 9" of shock travel and still maintain all the factory up-travel. This is a radius arm system, so there is a little bit of motion ratio also....but not much.
Metcalf
Expedition Leader
I am 5 3/8 bump pad to frame.
Comparing our weights, you are also about 720lbs heavier on the front axle.
It seems to confirm what i have been thinking, the aftermarket coils just seem like too much lift for me. I did find a 1.5 coil from rough country but it is a rough country coil and they say gas/diesel of course. The reports for how much lift are all over the place.
The truck is easily clearing a 33 inch tire now. 37s look like they would fit honestly with a little rework of the back of the fender or pushing the axle forward slightly.
mk216v
Der Chef der Fahrzeuge
The lack of transparency is frustrating for sure. Everyone wants to hold onto their secret sauce, which is understandable, but still frustrating to the engineers/enthusiasts not working at said company.
luthj
Engineer In Residence
At some point I found a chart which showed the front axle weights and possibly some spring rates for the solid axle F series front springs. I will see if I can find it. I agree though, most aftermarket spring kits are way to stiff. They are targeting those who want more lift, and don't want to get complaints about body roll or loose handling.
Metcalf
Expedition Leader
I posted the OEM ford table in post #32.
The stock springs rates, mine being over 400lbs/in, seems super excessive for the amount of shock travel and sprung weight to me.
I am typically of the opinion that you want the lightest spring rate that will hold up the vehicle to the position you want, preferably with a few inches of preload at full shock extension. This transfers less movement to the body while allowing more compliance in the suspension, especially in a beam axle where you get some transfer from side to side. On my 05 truck there is a LOT of inherent sway control from the built in bind in the radius arm bushing package. The sway bar is actually pretty dang small. I would rather fix roll/sway issues with the sway bar than spring rate.
luthj
Engineer In Residence
Even with 4,500-5,000lb front axle weight, I think 400lb/in is too high (for the 9-11" travel range). 350lb/in would be reasonable I think. If you are adding travel, you could go with even less, 325lb/in or maybe a bit lower. You would still be able to carry additional weight without riding on the stops, and your back won't be breaking on every bump. You would need a bit of preload depending on your desired ride height, but that should be doable.