F450 suspension ?

Anyone ever change out the front springs on their F450? Was curious what I could change mine out to mailnly for smoothing up the ride some but also lowering it by just a hair (will take out the rear lift block also to level it back out if need be). I don't tow anything but a jet ski and a small single axle trailer now days so I'm not concerned about reducing the weight capacity.

Anyways I found a thread with some spring info. What would be recommended for my setup?


4,400--5C34-5310-AGB Code W (4400 LB) 4WD
4,800--5C34-5310-AFB Code V (4800 LB) 4WD
5,200--5C34-5310-AEB Code T (5200 LB) 4WD
5,600--5C34-5310-ADB Code D (5600 LB) 4WD
6,000--5C34-5310-ACB Code C (6000 LB) 4WD
6,500--5C34-5310-ABB Code B (6500 LB) 4WD
7,000--5C34-5310-AAB Code A (7000 LB) 4WD

Btw my front springs currently on the truck are the 6,000 lb springs

if you weigh yours i bet the front is about 4000lbs

you could get away with the lowest spring rate IMO

even most loads don't transfer to the front much

My sclb was almost 5000 lbs with just me in it, so I'm sure yours is close to that if not more

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IMO you can use whatever spring the SRW superduties are using to lower/soften the ride up front. The f-450 is very close in weight to the srw frame/body wise up front as very little is changed. Much of the additional weight of a 450 is unsprung weight in axles,wheels/tires so it doesn't matter. And since your not hauling a 5000lb camper or a snow plow a lower rate won't hurt. The question is how low do you want it to sit.

Thanks for the replies everyone. So I'm thinking the 4,800 springs would be the way to go. Anyone know how far that typically lowers the front end?

footlong70 said:

IMO you can use whatever spring the SRW superduties are using to lower/soften the ride up front. The f-450 is very close in weight to the srw frame/body wise up front as very little is changed. Much of the additional weight of a 450 is unsprung weight in axles,wheels/tires so it doesn't matter. And since your not hauling a 5000lb camper or a snow plow a lower rate won't hurt. The question is how low do you want it to sit.

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F-450s have different bigger frames in the front IIRC.


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Have you looked into A/M offerings from Icon or Carli? That may improve the ride even more.

F450's shouldn't have blocks on the rear. If yours does they were added.
Most of your ride will come from the rear of the truck.
The front can be rather stiff and the back plush and it will feel nice. The other way, not so much.
The frame is different on that model 450. The weigh more too, my 450 with 1/2 tank of fuel and me in it was a little over 10,000#. They are pigs.

Damn so what options would I have then?

Really other than change the rear springs not much. Put air ride on it but thats $$$$. 450's are not meant to be grocery getters, you're seeing that. They are meant to have 4000# in the bed. Even then they don't squat that much.

Well shoot that blows but I do see your point and it is for sure a work horse, well more of a retired work horse now lol

The biggest thing I did to help unloaded was to run low pressure in the tires. I ran about 40 range in the back if I was driving for a while on the freeway. Even on the 16 I do the same but it has 17's so the tires are not that stiff to start with.

If you dont need the 450 anymore, why not trade it in on either a 250 or srw 350?

tbsimmons said:

The biggest thing I did to help unloaded was to run low pressure in the tires. I ran about 40 range in the back if I was driving for a while on the freeway. Even on the 16 I do the same but it has 17's so the tires are not that stiff to start with.

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Running lower pressure in the tires has always had me wondering if it'd help. I got the 19.5s and the tires on it are like rock hard so I'm sure that's not helping any.

6.0 Tech said:

If you dont need the 450 anymore, why not trade it in on either a 250 or srw 350?

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It's paid off and plus it's been kept in immaculate condition. Every time I take her out people always ask if it's brand new and I'm like um no it's an 08 lol

i gotta '10 450. we built a dump box for it. like 10' long, and just wide enough to cover the tires.

full of dirt, with a skid loader on a trailer we weren't close to bottoming out the suspension.

yes, their pigs. i also have the 19.5's on mine to.

what we did, was load it to the gills with what we thought would be the most we would ever put in it, not plumb full, but you get my drift, and then let out air pressure in the rear till the tires had about a half inch till they touched each other. your inner and outer duals on one side. and that is your new tire pressure.

as a tree trimmer, mines either parked not being used that day, or loaded. rarely is it empty unless its traveling to get loaded or traveling back after having dumped.

you decide how much pressure you need in your rears for yourself. whatever you decide on, if you go with a lower pressure just make sure you keep a close eye on the spacing on your duals. if you go with a "ride quality" pressure instead of a "work" pressure, and then load it, if your two tires touch cuz you forgot to air them back up the tires will get fking hot and tire wear will accelerate. my learning experience for you, lol.

as for the fronts.

on my rears, the axle is almost centered in my dump box. to the rear some, but pretty much centered. as such, the rear carries a vast majority of the load, very little of the load itself is carried on the front. so instead of changing springs, let air out of your front. i think my tires call for 90# or something, and i got like 65-70 in them. it was a huge improvement. keep a eye on front tire wear if you do let air out, as if it looks like it's wearing more on the outside of the tread and not the middle, you let to much out your running on your side walls. put some air back in.

but if you think your going to make this truck ride like a SRW, i want some of what your smoking. lol. it's a pig and will ride accordingly. though it can be improved some.

Correct the 450 frame is different, "Heavier" but minimally. The frame weight difference is less than 500 pounds. But call it a 500 pounds heavier for argument sake, cut that in half because the front springs are holding half of it, so 250 pounds additional on the front, divided between two springs is only 125lb extra per spring which is peanuts on a <8000lb(sprung weight) truck. The 450 stock springs have a higher spring rate for the payload(which you say is not required anymore), not so much the truck curb weight difference.

BTW
2016 models but same idea, as the frames ect are nearly identical
Curb weight of F-350 CCLB SRW Diesel 7734lb
Curb Weight of F-450 CCLB DRW Diesel 8589lb
A grand total of 855lb, subtract additional unsprung weight in axles, tires, rims, then divide by 2 as the front is only holding half the load. You really are talking peanuts... You can use whatever spring the 350 srw are using with very similar expectations.

Be careful running 19.5s at a lower pressure. Steel sidewall tires don't like to flex. I've had one come apart on a tire machine and it was a mess.

Alright guys so I dropped the pressure in the rears from 70 to 60 psi. Will see if there's any difference this coming week, running the fronts at 65 psi.

Thanks again for all the replies and sharing your ideas