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Discussion Starter · #1 ·
It occurred to me that adding a leaf spring is a common approach to increasing ride height and adding load capacity, so if a leaf is removed, would it not do the opposite?

I have a 118, it is my primary driver, I will never carry more than 1/2 ton or load the hitch with more than 2-300#, so the factory springs are an overkill. I will probably add air bags to allow for increased loads as needed.

I dislike the stiffness of the suspension, it rides hard and bounces, as well as riding higher than necessary.

Has anyone removed the secondary leaf spring?
 

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Fiat Ducato in Europe offers different suspension settings for cargo, passenger, motorhome, ambulance versions.
For example in the newer model (X290) FCA added composite leaf springs.

Passenger version as well as motorhome version offer more confortable ride for persons onboard.

Single leaf is the standard configuration of european Fiat Ducato.

From Fiat Ducato brochure (UK - http://www.fiatprofessional.co.uk/CMSEN/Pdf/Ducato_Goods_Brochure_nov14.pdf)
"... Up to 7 types of rear suspension are available:
- single leaf spring suspension;
- “comfort” type suspension with single leaf spring and anti-roll bar (opt 062);
- double leaf spring suspension (opt 077);
- double leaf spring suspension with increased ground clearance and anti-roll bar (opt 4GM), also available with 2500 kg permitted rear axle load (opt 057);
- composite suspension with increased ground clearance and anti-roll bar (opt 78Z), which enables a 15 kg weight reduction
- self-levelling air suspension (opt 555), also available in air-comfort version for heavy duty conversions (opt 075) ..."
 

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I wouldn't recommend taking a leaf out of the standard spring, because that spring was engineered to work like that. But ... Figuring out what part numbers are involved in any of the above and ordering those, and swapping them in, ought to be possible. Or you could have a local leaf-spring shop make something up. Don't forget to check/replace the bump stops if they are different, which they probably are.
 

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Discussion Starter · #4 ·
I wouldn't recommend taking a leaf out of the standard spring, because that spring was engineered to work like that. But ... Figuring out what part numbers are involved in any of the above and ordering those, and swapping them in, ought to be possible. Or you could have a local leaf-spring shop make something up. Don't forget to check/replace the bump stops if they are different, which they probably are.
My 118 has two leaf springs, one is full length, one is ~ 2/3 length of the longer spring. Load capacity is 4000#

If adding a leaf increases load capacity by 1000-1500# and raises the vehicle by 1-1.5", then wouldn't removing a leaf reduce the load capacity and lower the vehicle by about the same?

I've played with leaf spring suspensions and lift kits many times over the years, the only downsides to my plan are if the rear drops too much or the single spring is not stiff enough. Both of these scenarios are easy enough to test by just doing it.... so I'm going to do it this weekend.

I may need a spacer for the bumper or a small spring perch block to maintain consistent bumper spacing. Though honestly, does anyone think that a vehicle is really meant to hit those bumpers, ie wouldn't a hard enough hit lead to bumper overload and a tire to wheeltub impact??

It would be interesting to know what springs are installed on my vehicle and then compare those to the ones listed in MJAB's post. Anyone??

Pics and review to follow.
 

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I will follow your thread because im interested in lowering my 136.
re-arching my existing springs are going to run me 750 and 5 days down time.. I'd like another option.
Thanks
 

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Though honestly, does anyone think that a vehicle is really meant to hit those bumpers, ie wouldn't a hard enough hit lead to bumper overload and a tire to wheeltub impact??
In any other vehicle I've ever had including many vans, pickups, etc. the rubber snubber bumpers only come into play during extreme suspension movement situations (abuse). In the ProMaster however, these snubbers seem to be designed to actually act as helper springs. My van is nowhere near max GVW. I likely carry around 2500 lbs. of shelving, tools, etc. and the leaf springs regularly contact and compress the snubbers. Even at rest there is only about 1/2" of clear space between the bottom of the snubber and the top of the leaf springs. So while your use may not require as much suspension, many people who use these vans for work are putting those snubbers to use every day weather they realize it or not. This is also why the Sumo Springs version of the rubber snubbers might make sense for people who need something better than the factory snubbers, but don't want the expense and maintenance of a full airbag type system.
 

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It occurred to me that adding a leaf spring is a common approach to increasing ride height and adding load capacity, so if a leaf is removed, would it not do the opposite?

....cut...
Not always. It depends on leaf spring design. In some cases it may make little or no difference in ride height or functional spring stiffness -- hence little difference to normal ride quality.

In many cases multi-leaf springs are designed to have progressive stiffness. On a lightly loaded vehicle not all leafs would be put to work, but as the vehicle is loaded, the primary leaf flexes enough so that it comes in contact with the secondary leaf, thereby starting to load it from that point down.

I've seen some pictures of PM leaf springs when van was empty, and some do appear to have a different curvature for the shorter second leaf. In those cases removing it would do very little.


There is also issue of loads placed on leaf(s) during braking. As the primary leaf tries to twist, the secondary will contact the primary and help keep the axle from rotating too far, which "could" then release suddenly causing wheel hop during hard braking. Testing could rule this out.
 

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Discussion Starter · #8 ·
Yes, spring wrap is possible, spring torsion also, however single leaf spring systems are not uncommon, so it is more than likely that the second spring is a just "helper". If it was a three spring or more stack, I'd do it without thinking, but a two stack is a little more risky...

I'm have a spring shop look at specs to see if simply removing the secondary spring will work or if I need to do a re-arch too or if I need to do a custom spring.

If you do a search on line, there are many threads on removing a leaf to soften the ride, off roaders, commercial vehicles being used for non-commercial uses, hot rodders moding older cars, lowered street trucks, etc...

It may be that the single leaf in combination with an airbag system would be the ideal combination for maintaining capacity, softening ride, and reducing height. Clearly the way these vehicles are shipped is an overkill for non commercial users.

Feedback to follow.

Not always. It depends on leaf spring design. In some cases it may make little or no difference in ride height or functional spring stiffness -- hence little difference to normal ride quality.

In many cases multi-leaf springs are designed to have progressive stiffness. On a lightly loaded vehicle not all leafs would be put to work, but as the vehicle is loaded, the primary leaf flexes enough so that it comes in contact with the secondary leaf, thereby starting to load it from that point down.

I've seen some pictures of PM leaf springs when van was empty, and some do appear to have a different curvature for the shorter second leaf. In those cases removing it would do very little.


There is also issue of loads placed on leaf(s) during braking. As the primary leaf tries to twist, the secondary will contact the primary and help keep the axle from rotating too far, which "could" then release suddenly causing wheel hop during hard braking. Testing could rule this out.
 

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Dynamax REV Exceeds Rear GAWR

Fiat Ducato in Europe offers different suspension settings for cargo, passenger, motorhome, ambulance versions.
For example in the newer model (X290) FCA added composite leaf springs.

Passenger version as well as motorhome version offer more confortable ride for persons onboard.

Single leaf is the standard configuration of european Fiat Ducato.

From Fiat Ducato brochure (UK - http://www.fiatprofessional.co.uk/CMSEN/Pdf/Ducato_Goods_Brochure_nov14.pdf)
"... Up to 7 types of rear suspension are available:
- single leaf spring suspension;
- “comfort” type suspension with single leaf spring and anti-roll bar (opt 062);
- double leaf spring suspension (opt 077);
- double leaf spring suspension with increased ground clearance and anti-roll bar (opt 4GM), also available with 2500 kg permitted rear axle load (opt 057);
- composite suspension with increased ground clearance and anti-roll bar (opt 78Z), which enables a 15 kg weight reduction
- self-levelling air suspension (opt 555), also available in air-comfort version for heavy duty conversions (opt 075) ..."
I went to DOT scales straight from the dealer after buying Dynamax REV 24B. Rear axle was only 80 lb under GAWR without any cargo or passengers. When I use it I carry 5 passengers, 800 lb, and normal RV stuff in rear storage and therefore exceed rear GAWR by probably 500 lb. Maybe one of these options would help but what about tires? And RAM tech support told me there was no way to increase GAWR.
 

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In Europe there are several aftermarket companies that offer solutions for Fiat Ducato suspensions, most are for motorhome needing modifications since permanent higher load or to increase ride confort.
Companies like Al-Ko, Goldschimitt, Top Drive System, Dunlop Systems and Components, OMA (Officina Meccanica Ammortizzatori)

There are many different solutions: leaf spring with different performances, additional leaf springs, coil springs to complement leaf spring work, shock adsorbers, auxialiary air suspension systems, integral air suspensions, ...
It always better to contact their technical service (even if not willing to buy) since the result is changing the vehicle dynamic and it can be very dangerous if not done in a proprer way.

For motohomes the Fiat Ducato uses different suspension setup than van versions. There are also special chassis only Ducato versions with larger rear track.

Fiat Ducato versions to look at is X250 or 250, that is the project name.

Here, for example, there is a link to the Goldschmitt 2014-2015 catalog where one can find different solutions (also the other manufacturers have similar solutions).
http://www.goldschmitt.de/fileadmin/user_upload/FTP-Upload/Product-Catalogue_2014-2015.pdf
 

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I went to DOT scales straight from the dealer after buying Dynamax REV 24B. Rear axle was only 80 lb under GAWR without any cargo or passengers. When I use it I carry 5 passengers, 800 lb, and normal RV stuff in rear storage and therefore exceed rear GAWR by probably 500 lb. Maybe one of these options would help but what about tires? And RAM tech support told me there was no way to increase GAWR.
If by gross "allowable" weight rating you mean what the vehicle was certified to haul, I think he/you are right.

If springs or tires were only limitations towards whatever new capacity you want, then it would be easy. Leaf springs and tires with higher capacity are easy to obtain and relatively cheap.

But what about the wheels, bearings, axles themselves, or brakes?

I could see upgrading the entire assembly from the springs down to something in the 6,000- to 7,000-pound range but it wouldn't match the rest of the vehicle, and it wouldn't address whatever limits there are to the chassis itself (although the chassis is going to be overloaded regardless). And obviously with enough money someone could reinforce the chassis too similar to the way European builders sometimes fabricate an all new chassis for much heavier motorhomes (they use tandem axles but in a retrofit it would need to remain single axle).
 

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Has anyone removed the secondary leaf spring?
I removed the second spring to lower the rear. I needed to be less then 7'6" for the ferry. I usually carry 1/2 ton (as seen in photo) and the ride is fine. I will get the secondary springs re-arched someday, but after 7000 miles with some pretty heavy loads, I am in no hurry. Plus, the ride is so much smoother.

One of the consequences of lowering the rear is I have had to unscrew and wedge my headlights down... people kept flashing me. See photo http://www.promasterforum.com/forum/images/smilies/confused.gif
I sure wish there was an adjustment screw.
 

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I removed the second spring to lower the rear. I needed to be less then 7'6" for the ferry. I usually carry 1/2 ton (as seen in photo) and the ride is fine. I will get the secondary springs re-arched someday, but after 7000 miles with some pretty heavy loads, I am in no hurry. Plus, the ride is so much smoother.

One of the consequences of lowering the rear is I have had to unscrew and wedge my headlights down... people kept flashing me. See photo http://www.promasterforum.com/forum/images/smilies/confused.gif
I sure wish there was an adjustment screw.
Rick.. was that a very hard job to do?
Do it yourself? If so, maybe you can PM me with a bit of instruction?
I like the way it looks now and the smoother ride interests me.
Did you have to get new U-Bolts?
thanks.. Please expand on your post to help others who want to do this mod.
thanks given and thanks again.
 

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Secondary spring removal

Overall the removal is simple if you have a jack and a couple of stands.
This is the first time I have every posted anything, thanks for the response!
So... I wish I had taken more photos, but here is the simplified process.

1. Jack up the rear until the tires are clear off the ground and set jack stands
2. Remove the u bolts, the nut on the top plate, and one bolt on the shock.
3. The axle will drop down and the spring is free to remove.
4. The U bolt plate will need to be drilled out for the axle locate bolt to slip through.
5. The U bolts work fine but the brake line cable supports on leaf spring will need to be squeezed and zip tied to work.
6. locating the bolt for the shock was the most difficult part, I cross threaded it on the first try. You have to use the jack to raise the axle for alignment.
7. I don't remember all the torque settings for the bolts, so you will have to take some notes before removing anything.

This process took about an hour. The overall reduction in height is about 2.5".
This was totally worth saving about $12 per trip on the ferry.
 

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I removed the second spring to lower the rear. I needed to be less then 7'6" for the ferry. I usually carry 1/2 ton (as seen in photo) and the ride is fine. I will get the secondary springs re-arched someday, but after 7000 miles with some pretty heavy loads, I am in no hurry. Plus, the ride is so much smoother.

One of the consequences of lowering the rear is I have had to unscrew and wedge my headlights down... people kept flashing me. See photo http://www.promasterforum.com/forum/images/smilies/confused.gif
I sure wish there was an adjustment screw.
Rick, your van looks great; with ride height similar to European Ducatos instead of rear being jacked up in the air. If anything it looks slightly lower in rear than in front, but that could be angle of the picture. Either way it looks far better to me than stock.

Do you know what your total height is now? Any idea on how much under 7'-6" it sits?
 

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I removed the second spring to lower the rear. I needed to be less then 7'6" for the ferry. I usually carry 1/2 ton (as seen in photo) and the ride is fine. I will get the secondary springs re-arched someday, but after 7000 miles with some pretty heavy loads, I am in no hurry. Plus, the ride is so much smoother.

One of the consequences of lowering the rear is I have had to unscrew and wedge my headlights down... people kept flashing me. See photo http://www.promasterforum.com/forum/images/smilies/confused.gif
I sure wish there was an adjustment screw.[
/QUOTE]

There are two rubber plugs (one per side) at the base of the windshield, near were wiper arms are attached, that give access to the headlights vertical adjustment screw. It is needed a long 6 mm hexagonal / Allen screwdriver.
It is easier to start from drivers side, with hood open, since one can see where the screw head is (it is a wite part with to shaped like a cone).

Otherwise can be removed the triangular covers over the headlamp, that also gives access to the headlamp horizontal regulation.

 

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There are two rubber plugs (one per side) at the base of the windshield, near were wiper arms are attached, that give access to the headlights vertical adjustment screw. It is needed a long 6 mm hexagonal / Allen screwdriver.
It is easier to start from drivers side, with hood open, since one can see where the screw head is (it is a wite part with to shaped like a cone).

Otherwise can be removed the triangular covers over the headlamp, that also gives access to the headlamp horizontal regulation.
Thank you so much, that was so helpful. :)
 

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Rick, your van looks great; with ride height similar to European Ducatos instead of rear being jacked up in the air. If anything it looks slightly lower in rear than in front, but that could be angle of the picture. Either way it looks far better to me than stock.

Do you know what your total height is now? Any idea on how much under 7'-6" it sits?
I just measured the rear with the heavy sprinter bench seat. The height was 7'3" and the front for comparison was 7'1 1/2" . So it looks like it is almost level.
 

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Thank you very much for your post! Just getting ready to do the same here! The van has to ride & handle much better! Did u remove the entire spring set, or just remove the shorter Leif?
 
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