Leaf Spring F-350 suspension help

[RangeDrive]

Hello ExPo,
I have a 1999 7.3 F-350 that I'm trying to build out to a family truck camper rig. It currently has an unknown 6 inch lift with 35s and drives really rough. I'm looking at options on what is a good suspension brand to go with, to smooth out the ride. I was thinking about keeping the springs themselves, and going with a Bilstein shock, as well as correcting the track bar setup, because I know that's not correct, and then seeing how it rides. I know its a heavy duty truck, and will always ride rough, especially unloaded, but right now its what I would consider excessive.

My standards are probably a little high, coming from Tacomas with Icon suspension, and a Ram 2500 with a full Thuren Setup, but I still think this truck will be able to ride comfortable enough for our needs.

 

[Buddha.]

I like bilstien shocks but I don’t think they’re gonna make anything smoother.

I know on the square body ford you could reverse the shackle or something for a smoother ride. Not sure if the ‘99 was the same.

 

[Macfly]

I have the Carli Pintop set up and it's basically atrocious on the road, as a friend says, it finds bumps where none exist. It may be better once the build is completed, but right now it's awful! I see a lot of chatter about the Liquid Spings brand, which could be worth exploring, depending on the weight you're planning to add.

 

[RangeDrive]

I have the Carli Pintop set up and it's basically atrocious on the road, as a friend says, it finds bumps where none exist. It may be better once the build is completed, but right now it's awful! I see a lot of chatter about the Liquid Spings brand, which could be worth exploring, depending on the weight you're planning to add.

Carli or Thuren do not make a system for the 99-04 F-30s

 

[tacollie]

The Fords with leaf sprung front ends ride rough. Without knowing what's on the truck is hard to say what to do. Shocks may help.

Check your tire pressure. I've spent a lot of money on suspension but if I don't drop the tire pressure when we pull the camper off our truck rides rough. 45psi unloaded versus 55psi loaded.

 

[IdaSHO]

Agreed about tire pressures, but be certain to consult a tire inflation chart before dropping PSI.

Running the high load Toyo AT2's we do, we roll loaded with the camper at 60PSI front, 75PSI rear.
Empty, I drop it to 45PSI front, 40PSI rear

Those numbers (loaded) are for warmer months. Colder months I tend to drop PSI for a better ride even when loaded.

 

[RangeDrive]

Good advice. The tires are already at 50 PSI when unloaded, and they're 35/12.5/18s. For now, I think I'm going to buy a good quality track bar drop bracket, and an adjustable track bar and try to get the axle centered properly. It really feels like its binding, and not allowing the springs to flex as they should. On a trip across the country, it broke a front spring shackle, and replacing it was very difficult due to the track bar pulling the axle to the drivers side HARD

 

[NatersXJ6]

If you broke a shackle, it is probably fair to say something is very wrong with the suspension design. Likely the shackles are too short and not letting the spring flatten far enough to actually absorb bumps. You might consider building a small frame to measure the spring rate and dimension changes, off the vehicle, but you quickly slide down the slope of “custom suspension design” without warning.

6” seems like a lot, but I haven’t driven something with front leaves in a long time.

 

[andy_b]

I have the same truck but with 2" a leveling kit in the front and otherwise stock springs.

As @IdaSHO mentioned, weighing the truck and adjusting the tire pressure accordingly makes a big difference.

I have Fox 2.0s with reservoirs. These definitely helped smooth out the ride but are currently underdamped. A truck this size probably needs 2.5s or 3.0s. Fox doesn't make a shock in this size for this application but Icon and ADS do. The may be worth looking into for better ride control.

I also have Airlift airbags at all four corners - these include a bump stop in the bag. The fronts I run at 5-10psi (I think the minimum is 5psi). The set have probably made the biggest difference of all both as a bump stop and to help with old springs in the rear.

Custom springs would probably make a huge difference overall to the quality of the ride.

 

[pappawheely]

Most off the shelf suspension kits are built to satisfy the amount of lift, not the ride. They have to make sure if you buy a 4 inch lift, you get 4 inches of lift; regardless of the loads or uses. They are typically over sprung. The best way to get a great ride and the proper function is to go with custom progressive springs. You have a big heavy truck. It's like a big heavy person, off the rack probably won't fit. I have progressive springs from Atlas. They are matched to the weight of my truck. Actually, the rear's are a little heavier than I need, but that's because I wanted to haul anything from a slide in camper to a pop-up. My truck rides incredible for a one ton. I had a friend in the truck the other day and he commented how his truck gets pounded on the same section of road.

 

[Broncogearhead]

I am not saying you cant achieve the ride you want with better leafs, but another option is to use an 05* axle and convert it to coils. Not exactly cheap, but it was one of the best things I did to my 04 f350. Much better turning radius (the main reason I did the swap) but also bigger breaks and larger stub shafts. I used icon coils and fox shocks. The ride is night and day different than when stock or with a 4" leaf set up.

 

[BikePilot]

I suspect that you could do a DYI version of a Thuren-style configuration by ordering up custom Deaver leaf springs and custom valved King 3" shocks. It should ride about as well as anything once that's all done. CJC or Carli may have something on the shelf for specs. Note that for shocks it's all about the valving--saying Kings or whatever ride great or terribly doesn't make any sense without talking about the valving used. You have to dial in the valving for your specific use, springs, preferences, etc., to get any sort of decent performance. That's why Thuren and Carli work so well.

 

[glock7018]

I recently put a set of Alcan custom leaf springs under the front of my excursion. Worth the price I think. Ride way nicer than any stock 05+ superduty. Take your truck fully loaded to a truck stop and use the scale there. Give them your axle weights and they can make a set of springs tuned form the weight.

 

[LuckyHenriksen]

You can check out the Super Duty offerings from Old Man Emu, they offer full replacement front and rear leafs for the early Super Duty trucks. I just recently installed their entire kit onto my 2005 F350, haven't had a chance to load it down and go for a long trip yet but its definitely gained me a couple inches in height and rides pretty decent for a big pickup. Here are a couple photos of the '05

IMG_0007 by Steven Henriksen, on Flickr

87DE7148-4B6F-404D-81A0-0B5CC79B1A11 by Steven Henriksen, on Flickr

3F0B2AF3-50D3-485F-8047-DDF44246E7C1 by Steven Henriksen, on Flickr

Also, I just picked up a set of their front springs and other parts to overhaul my old leaf sprung 2004 F350. Just got these in on Thursday so they are still sitting on the pallet in the shop

IMG_0925 by Steven Henriksen, on Flickr


Another option to look into could be Carli, they sell a full 4.5'' leaf kit (Deaver's) for the Excursions, which share the same springs as the regular pickups. I haven't looked into it enough to know if there is a reason why it wouldn't work, but they have the springs for sale separately or as a package with the expensive custom tuned Kings.

Excursion Components – Carli Suspension, Inc.

www.carlisuspension.com

 

[rruff]

Good advice. The tires are already at 50 PSI when unloaded, and they're 35/12.5/18s.

A note on pressure... you can drop that way down when unloaded. My tires are a little wider and a run 35f and 30r when empty. Handles great, wears straight.

Tire Size	25 psi	30 psi	35 psi	40 psi	45 psi	50 psi	55 psi	60 psi	65 psi	70 psi	75 psi	80 psi
35x12.50R18	1820 lbs	2075 lbs	2335 lbs	2530 lbs	2735 lbs	2910 lbs (D) 118	3115 lbs	3295 lbs	3415 lbs (E) 123	3630 lbs	3795 lbs	3970 lbs (F) 128