What do to for 2007 F-550 4x4 suspension?

[spearomax]

I am currently building out a camper on a 2007 F-550 4x4 platform. The build is in progress (I'll start a build thread one of these days!) and won’t be complete for many months but I want to get my ducks in a row for the suspension for when the final weight is known. I know very little about suspension so I’m looking for some guidance based on what my early research has produced:

I want to do a custom leaf spring in the back based on the final weight, but that is about all I know. I think I will need a 2.5 inch lift in the back and 4 in the front to fit the wheels and tires I want (super single conversion Continental MPT 81).

I will probably go with deaver for the leaf springs, but I am wondering what to do about the front suspension. Most people seem to go with a coil over. From what I see, there are no kits for the 2007 f-550. Will an off the shelf option work? Can I simply measure the distances I need like Accu Tune outlines in this blog? Then purchase the right size coil over from them?

Do I go with a custom spring maker like Coil Spring Specialties and put a normal shock inside it? I'm really just a suspension noob.

The ride is really rough on-road right now—I am assuming that custom leaf spring and coil over front suspension will be the best option for both on and off-road driving (air ride systems are too much for me).

Thanks for any guidance.

 

[spearomax]

I will also add that I am not attached to the wheels/tires and lifting it - I just figured if I was doing custom springs/shocks, may as well have the option. If it is significantly easier/cheaper to just stick with 35 inch tires I will - so long as the ride improves on-road (and off).

 

[1stDeuce]

F450/550's already have coil front suspension, so coilovers not really a big improvement, and likely a lot of fabrication to incorporate. I would think F350 springs would work, and likely be a softer rate that the F550 OEM coils. Rear springs made for the correct weight of the truck would be far better than the stock springs, which are probably rated for 2x or more the weight you'll be carrying. Alcan Spring in Grand Junction CO can probably also do a nice job of making you a set of springs too.

Spring rates are VERY important to ride quality. Going too low will make it feel like a 1970's Cadillac, while too stiff will make it, well, ride like it presently does... The aftermarket by and large has not figured this out, and you get what you get... If money is no object, your best bet might be to go with name brand front springs, or an F350 stock spring and a coil spacer if you need a little lift, custom rear springs, and King shocks that can be custom tuned...

FWIW, my experience with F550's is firefighting brush trucks. We have found that lifting them much at all makes them drive like absolute crap, rather than just crap, which is kinda how they drive stock... The rear seems to get really loose with much lift at all, and the front suspension feels like it's all loose and banging around to me anyway... I would recommend staying with the lowest amount of lift that you can make work.

One of the issues with the ride is the stock 225 or 245 size tires, which have almost no sidewall and a LOT of pressure. The HEAVY front and rear axles don't help either, but there's not much you can do about that... Going with a larger tire and a bit less pressure will improve the ride. I messed with one truck on 285/70R19.5's and they do a decent job of working with the stock height but the rear duallies needed a spacer or you need different wheels. I think 265's would work without spacers, and without lift on the stock wheels. Either would be a HUGE improvement in "off road" capability over the stock tire size, and the wider tire on stock wheels will resist coming off the bead better at low pressures you may occasionally need offroad.

Good Luck!!

 

[Ole Chipper]

Think I would look into a air bag suspension. This way you can adjust height and ride to your liking on the fly.

 

[spearomax]

F450/550's already have coil front suspension, so coilovers not really a big improvement, and likely a lot of fabrication to incorporate. I would think F350 springs would work, and likely be a softer rate that the F550 OEM coils. Rear springs made for the correct weight of the truck would be far better than the stock springs, which are probably rated for 2x or more the weight you'll be carrying. Alcan Spring in Grand Junction CO can probably also do a nice job of making you a set of springs too.

Spring rates are VERY important to ride quality. Going too low will make it feel like a 1970's Cadillac, while too stiff will make it, well, ride like it presently does... The aftermarket by and large has not figured this out, and you get what you get... If money is no object, your best bet might be to go with name brand front springs, or an F350 stock spring and a coil spacer if you need a little lift, custom rear springs, and King shocks that can be custom tuned...

FWIW, my experience with F550's is firefighting brush trucks. We have found that lifting them much at all makes them drive like absolute crap, rather than just crap, which is kinda how they drive stock... The rear seems to get really loose with much lift at all, and the front suspension feels like it's all loose and banging around to me anyway... I would recommend staying with the lowest amount of lift that you can make work.

One of the issues with the ride is the stock 225 or 245 size tires, which have almost no sidewall and a LOT of pressure. The HEAVY front and rear axles don't help either, but there's not much you can do about that... Going with a larger tire and a bit less pressure will improve the ride. I messed with one truck on 285/70R19.5's and they do a decent job of working with the stock height but the rear duallies needed a spacer or you need different wheels. I think 265's would work without spacers, and without lift on the stock wheels. Either would be a HUGE improvement in "off road" capability over the stock tire size, and the wider tire on stock wheels will resist coming off the bead better at low pressures you may occasionally need offroad.

Good Luck!!

Very helpful, thank you!

 

[LuckyHenriksen]

Check out the front spring options from Carli or Icon for the 05-07 Super Duty. They have 2.5-4.5'' lift options and matching shocks at various levels of expense. Carli also makes a nice adjustable Panhard bar with solid ends to help keep the axle aligned after a lift.
Also, I just installed the ARB Old Man Emu front springs and shocks on my '05 F350 and so far I am liking the height and ride quality. They offer approximately 2.5'' of lift over stock. Great budget friendly option IMO.

Your F550 sounds like a fun project! I have an '04 F550 Lariat 6 speed that I am hoping to convert into a poor mans Earth Roamer someday. For now it's just my farm truck though.

 

[spearomax]

Yes, that is the plan - to build it all out and see where I'm at with comfort etc. Then start to figure out suspension. thanks very much