Rear Leaf Springs Ford E350

[wearenh]

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Reading another thread on teeth rattling got me thinking about the Leaf Springs .... So
far I have already added the Firestone Ride-Rite Airbag system (with onboard inflator)
and have recently upgraded to Koni FSD shocks ... both of these made a big difference
but I got to wondering if they are working together to help compensate for leaf
springs that are 1. Undersized from the factory and 2. worn out

I went under the motorhome and saw that the springs are in a "frown" ... if you look
at the attached diagram, the "C" dimension is negative... I also counted the
leaves, to determine whether I have the 43-1041 (5 leaves) or 43-1085 (9 leaves)

I have the 43-1041 (5 leaves) which has a stated spring capacity of only 2775 lbs
This is problematic, since the last time I was FULLY loaded (ok, overloaded)
I went over the scales at 8940 lbs on the rear axle. I am thinking that the springs
being in a frown, and looking at the stated capacity, the only actual reason I have
ANY springs are the airbags!

Replacing the springs with new ones should help if they are worn out, but even then
2775 is way under what I am loading these springs. So, I am going to go to Heavier
Duty springs. However, the 43-1041HD (7 leaves) only increases the capacity to 3750 lb

Has anyone here replaced their 43-1041 springs with 43-1085 springs ??

If I go to the 43-1085SHD it will give me adequate capacity of 5000 lb but the
person I spoke to at Stengelbros said it would ride harder... I'm thinking that
the "ride harder" argument only would apply if I am replacing a spring that
already has adequate capacity with a spring that has more. Since I am replacing an
underrated spring that is fully compressed (even frowning), I don't think that
the "ride harder" argument applies.

thoughts??






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[tatest]

The chart is for vans. The bare chassis, cab-chassis and cutaway all have different leaf spring packages, with negative arch.

[SoCalDesertRid1]

The E350 cab/chassis springs are likely different than the van springs. Your cab/chassis probably has upper overload springs, in addition to the main spring packs.

You are right though, 5000 lbs/pack springs for your ~9000 loaded axle weight will be just about right.

[Naio]

boogie_4wheel wrote:
On an empty truck, a heaver-capacity spring would cause a harder/harsher ride. Since this is a motorhome, and is always 'loaded', the difference is reduced.

x2.

Also, look into custom leaf springs. I found they were the same price as the aftermarket ones like you are looking at. And customized to fit your exact usage!

[ron_dittmer]

wearenh,

The chart shown above is for an E350 van, not an E350 cut-away chassis which would very likely have higher weight ratings.

[boogie_4wheel]

On an empty truck, a heaver-capacity spring would cause a harder/harsher ride. Since this is a motorhome, and is always 'loaded', the difference is reduced.

I think that you will end up reducing the air pressure in the bags so that you end up with very similar ride characteristics. Currently, a lot of the weight is carried by the bags. The newer heavier springs will take more load, reducing the weight that is carried by the bags.