F350 Suspension Setup for near GVWR Adventures

[danjr]

Hello All,

Seeking some advice from the forums.

We've got a 2013 Ford F350 CCSB SRW. Lots of aftermarket goodies including winch bumper, Icon 2.5" kit, 37's, 4.88 gears etc. I purchased the truck with the current suspension setup and am looking to make some changes to:
1-Address minor nose high rake when unloaded
2-Handle the weight of our 2010 Hallmark Guanella
3-possibly recenter rear axle inside of wheel well to better clear the 37's during articulation (minor issue and not a driving consideration)

I've weighed the truck as follows:
Unloaded: ~7900lbs 4520F/3380R
Fully loaded: ~10640 5020F/5620R (this may get another 400ish lbs on the hitch from some storage boxes I'm rigging up)

I've also taken measurements: to fender wheel on center with the hubs and find that the truck is just slightly higher in the front (~0.5") when unloaded. When the camper is loaded the rear of the truck drops roughly 2".

I did have some Timbren SAS's on, but have since removed. This did prevent about an inch of drop and likely helped with stability, but wasn't getting much suspension travel-translating to a harsh ride offroad. Driving the fully loaded truck without the timbrens the ride seems better. Truck does contact overloads at times-no harsh bumps but its a bit noisy as they engage and disengage.

Truck will likely be loaded with the camper roughly 90-95% of the time. We live in CO and are out in the mountains every weekend regardless of the season.

Options I'm considering:
Option 1: Add a 6-7" block in the rear (replacing factory 4" block) and accounting for drop of rear suspension when loaded-should net a level rig when loaded and a 2-3" rake when unloaded ~$300
Option 2: Add a 5" block in the rear (replacing factory 4" block) should level the rig when unloaded, and add Air Springs (leaning towards Hellwig Big Wigs from what I've read) ~$1000
Option 3: Go with an aftermarket progressive leaf pack providing significantly better unloaded ride at unloaded level height and add Air Springs ~$1800
Option 4: Go with an aftermarket progressive leaf pack built for the fully loaded truck ~$1300

Option 1 is a set it and forget it option-never worry about the air springs, etc. Cheapest option. Unloaded ride comfort not the best
Option 2 adds complication of air bags, but could be a better route for being able to level on off center load, and leveling the truck at campsites
Option 3 is the most expensive route but would likely make for the perfect ride condition
Option 4 might ride pretty rough when unloaded, but I'm not sure if it would still ride better than the factory non progressive springs

Help is greatly appreciated on making sense of these options. I only want to do this once. Thanks!

 

[Betarocker]

If you go with a taller block, look at One Up Offroad traction blocks and 3/4" U-bolts. Control axle wrap. Add air bags to deal with loaded sag.

 

[Betarocker]

 

[McCarthy]

The only thing the larger block does is give the appearance the squat is gone, it does nothing to actually help it. Purely cosmetic. I'd go with a nice set of airbags.

 

[MR. ED]

Just a quick note... I think that the front and rear fenders are different heights off the ground/hubs. I put some 2inch lifted Bilstein springs up front on my rig and I think they were made for a diesel because it popped the front up more than 2 inches. I get the Baja race truck look with a full load in the back. Anyway I eyeballed down the side (without my glasses) and thought they seemed to be different elevations. Never went back with the laser to check. Sounds like you already have a pretty nice set-up with the Icons. If the campers on there 95% of the time leave it alone and re-adjust your headlights a little bit. If it still bugs you throw on a compressor and airbags. Good luck with your project

 

[IdaSHO]

We are at 12,300lbs as pictured during a recent trip.
Typically we roll at <11k. This was an exception primarily due to COVID.
We didn't stop for anything except water and fuel for a near 5,000 mile trip
Stock-stock-stock, except air bags in the rear.

It does great, but we are very dependent upon the bags.
A custom leaf pack is on the list of to-do's

 

[fatkins]

My experience: Installed 2 5 pintop suspension on my f250 with pop-up camper. Added superspring to oem spring in an attempt to bring the rear level with the front. Still a bit low so swapped ome, lift block, superspring for 4.5 deaver springs. Truck handles better on and off road, sits lever and much smoother ride.
Possible axle wrap with large lift blocks?

 

[Deleted member 9101]

Blocks and bags are a bandaid fix. Get a set of new springs made and fix it right the first time.

 

[McCarthy]

Blocks and bags are a bandaid fix. Get a set of new springs made and fix it right the first time.

Blocks I completely agree with, but airbags aren't a bandaid fix in my opinion unless you have a certain weight on your truck full time. Mine for instance, rides around empty about 70% of the time, and the other 30%, frankly, it's way over loaded. If I had a leaf pack built for that, it would be undriveable the majority of the time. With airbags, I can have 5 pounds in them, stock like ride, and 30 seconds later have 80 pounds in them where 4000lb's barely squats the truck.

If a truck carries a 4000lb camper its entire life, without question get a proper leaf pack built. For everyone else, there's airbags.

 

[danjr]

Thanks to all for the input. Based upon our primary use of the truck and the feedback here I'm leaning heavily towards a custom set of springs to ride at desired height when fully loaded. I've heard great things about Deaver, and am leaning that direction. Those who've had custom springs built, any insight as to what was needed, the order process, etc. would be greatly appreciated. We may wait until we have a few other things done to the truck such as the rear boxes I mentioned to ensure we have a clear fully loaded weight. Can run on the Timbrens in the meantime as we're approaching winter season which means a lot less offroad than summer.

 

[Betarocker]

Blocks and bags are a bandaid fix. Get a set of new springs made and fix it right the first time.

This not entirely true. The taller block is the only thing giving an F350 a 1ton rating over the 3/4ton rating of an F250. Sure there are options for towing and camper packages that have auxiliary leafs, but all things equal it is only the block.
I run the stock leaf w/ aux leaf , 8" OUO traction block with large gusset bars, and Riderite airbags in Daystar cradles. Unloads, I empty all the air from the bags to maintain a compliant ride, but can easily inflate as load requires.
Certainly a bag can fail, but broken leaves are much more prevalent.

 

[danjr]

Can anyone help to share the benefit of having the springs designed for use without Factory blocks? Some would say axle wrap but I'm not buying that if its the factory design. Main reason I ask is because I know Ford designed the F250 with 2" blocks and F350 with 4" block. I do understand the extra 2" in F350 is just to deal with sag from additional load capacity. However, it seems like there should be a reason they at least put a 2" block in for the F250 instead of just using Spring on 250 and 2" block on 350. Not sure why Ford would do this when could have just designed a leaf spring sans block unless it was needed? Does this have to do with clearance of axle components, brake lines, etc.? More just interested in any considerations or the why of moving from a factory block to no block with aftermarket springs.

 

[Betarocker]

I had soft 5" Icon springs with 1" block on my old truck and needed traction bars to control axle wrap. Snapped the Fabtech ladder bars w/ shackle chassis mounts that I originally installed before swapping to One Up Offroad.
Current truck uses stock leaf packs, even keeping the extra load leaf, OUO 8" traction blocks with OUO traction bars, and air bags for the last bit of load taming.

If a leaf spring is soft enough to allow the axle to move in a vertical path (slight rearward elliptical movement actually due to the shackle), it is also soft enough to wrap. Large engine full size trucks have enough torque to wrap the axle under acceleration and it gets even more pronounced as the weight increases. Engine brake, downshifting or higher compression deceleration will wrap the pinion opposite.

Ford, and others, tried to control wrap by mounting the shocks opposingly, one forward of the axle, the other rearward. Also this does is unbalance the suspension and torque axle weird.

The only way to not have axle wrap is to accelerate incredibly slowly, have a leaf pack so stiff that it doesn't actually move, or use well designed traction bars.

Since having traction bars on both trucks, I will always make that the first upgrade on any fullsize vehicle with leaf spring suspension. Even in full stock configuration.
Not all bars are created equal. Many of the cheaper designs bind during axle path movement, or use inferior or undersized elements.

 

[McCarthy]

I had soft 5" Icon springs with 1" block on my old truck and needed traction bars to control axle wrap. Snapped the Fabtech ladder bars w/ shackle chassis mounts that I originally installed before swapping to One Up Offroad.
Current truck uses stock leaf packs, even keeping the extra load leaf, OUO 8" traction blocks with OUO traction bars, and air bags for the last bit of load taming.

If a leaf spring is soft enough to allow the axle to move in a vertical path (slight rearward elliptical movement actually due to the shackle), it is also soft enough to wrap. Large engine full size trucks have enough torque to wrap the axle under acceleration and it gets even more pronounced as the weight increases. Engine brake, downshifting or higher compression deceleration will wrap the pinion opposite.

Ford, and others, tried to control wrap by mounting the shocks opposingly, one forward of the axle, the other rearward. Also this does is unbalance the suspension and torque axle weird.

The only way to not have axle wrap is to accelerate incredibly slowly, have a leaf pack so stiff that it doesn't actually move, or use well designed traction bars.

Since having traction bars on both trucks, I will always make that the first upgrade on any fullsize vehicle with leaf spring suspension. Even in full stock configuration.
Not all bars are created equal. Many of the cheaper designs bind during axle path movement, or use inferior or undersized elements.

Great info, thanks for sharing. Do the traction bars make it ride any better, or just prevent axle wrap?

 

[Betarocker]

I fully redid the front too. Progressive 7" springs, adjustable radius arms, and specifically valved Fox shocks. That alone improved the ride over stock. The traction bars mostly come into play during acceleration, but also on loose surfaces where wheel slip and grip would wrap.