New leaf springs question

[TheBluebird]

My 2003 Concourse sits very low to the ground in the back. I took it to a shop and they showed me that my leaf springs are sagging. Instead of a smile shape they are sad-shaped! I'd just had the rig professionally weighed on all four corners and I have not overloaded it. The guys at the shop said this sagging happened over time. I think they said the van chassis springs just cannot handle this load over time.

I'm taking it to Tampa Springs in Ocala to have custom leaf springs on Wednesday. Has anyone replaced their leaf springs? What is your experience? What should I ask the shop as far as how much support I want? I will be bringing it fully loaded and will make that clear when I drop it off. I don't want them to give me more than I need. I also, of course, want to make sure it will be reasonably level as they won't be doing any work on the front end.

Appreciate your thoughts, comments and suggestions.

[Blue~Go]

Just so you know, I believe the Ford rear leafs are always "sad" shaped when the suspension is loaded (i.e. sitting with wheels on the ground). Mine is *way* underweight on the rear axle, and sits quite a bit higher in the rear than the front, but the rear leafs are still "sad" shaped. (If I want to be level on flat ground, I have to put Lynx blocks under the front wheels - that's how perky it sits.) So I don't think the rear leafs ever sit "smile shaped" at all. I think the sprung down shape is normal.

However sagging in the rear isn't great -- but I think the "sad shaped" rear leafs may be a red herring.

Since you have a later model, you probably have Mor-Ryde suspension (rubber inserts) on the rear leafs. They are known to tear and go bad. I would have that checked first since you are sure you're not overweight on the rear axle.

On a previous truck I had a rear leaf added (that was inexpensive). But, that truck also rode softly, so the added leaf was just perfect (restored the perk, didn't wreck the ride). Given the typical rear suspension ride of the E-350 cutaway (can be a bit harsh, hence why they added the Mor-Ryde), I would be reluctant to just add another leaf on an E-350 cutaway (not saying you are doing that). Harsh ride in the rear is the known enemy of the E-350 (and I think E-450 cutaway).

If you do want to change springs, you might check into the parabolic rear leafs. When I was working on improving my handling, but also trying not to make the rear too harsh, this was mentioned to me as a solution that is used on E-Series ambulances (as you can imagine they don't want the rear to be harshly hopping up and down as they stick needles in and etc.). However, they were quite expensive, and I managed to tame mine another way (kept the parabolics in mind in case I needed them).

[TheBluebird]

Ok, that's very helpful. Would I be able to see the Mor-Ryde by looking at the springs? Because I don't see them. My main issue is that it seems I have no rear support at all. The tiniest bump is magnified as a big shudder. Actually my biggest issue is my rear sits far too close to the ground, probably 7 inches. I'm hoping new springs will raise it up. It doesn't take much for me to bottom out.

[chin_k]

There are a few threads on the MorRyde, and here is one example, where you can see a few pictures of what it looks like:

viewtopic.php?f=4&t=812&hilit=moryde&start=10#p7155

[Blue~Go]

PS: Just thought I'd mention about airbags, because you may hear them recommended. From what I understand, the time you may want to use airbags is when you have something with wildly varying loads and not when you have a heavy load consistently. Like say for example you have a light little SUV and all is fine as you drive it normally. Then you tow something on the weekend (this presumes you are within tow ratings). The rear sags. BUT, if you made it so the rear wouldn't sag while towing then you'd be driving a super harsh vehicle most of the time when you are not towing. Enter airbags. You can adjust them to make the vehicle not sag for those times you are towing, and then have them out of the picture when not towing.

But of course the Chinook has basically the same load all the time. There is no time you "remove the house" and just drive around a bare cutaway (at least we hope not ). So then what you want is a more "permanent" solution vs. the adjustable nature of airbags. At least as I understand it. But I get the feeling that they are sometimes recommended as a band-aid approach when something else would be more appropriate.

If the above is not correct, I hope someone who knows more will let us know.

PS: While shocks don't support the rig, they do affect the ride and handling to some extent. So just make sure you have good ones in good condition so they aren't muddying the waters. I went with the Koni FSD, but there are a number of good choices.

[pdemarest]

Slightly off topic but wondering if anyone out there has installed those Shulastic Springs? Basically sort of the Moryde principal but applied to the rear of the leaf springs. Apparently they give some lift with a softer ride but mainly address the side-to-side rocking that occurs when entering or exiting driveways.

On topic, I was able to get rid of a lot of that rear end shudder over bumps just by running the rear tires at 60 psi. When I got my rig the owner had the tires at 80 psi but I found that the ride was way too harsh. Also changed out all my shocks to Bilstein Comfort RV shocks - big improvement in the ride.

[Blue~Go]

I strongly considered the Sulastics and would have installed them if I could have gotten a set in time (I was at a shop already doing suspension work and tried to order a set in on my own). Also, the Sulastic folks gave contradicting advice as to which size, which didn't help my confidence in making a quick decision.

I don't understand how they would attenuate the side-to-side rocking at driveway entrances though. I found that upgraded anti-sway bars (there actually wasn't one at all in the rear, stock...) did that very well, but that makes sense to me due to how the bars work to tie the two sides together. Maybe I'm missing something about the Sulastics? I thought they simply softened the rear leafs a bit, kind of like Mor-Rydes but slightly differently.

I considered them in order to address the harshness of "even" bumps in everyday driving -- which were amped up with the large anti-sway bar I had added (which did wonderful things except for that). As it turned out, the adjustments I did make (smaller bar, slightly softer rear shock setting) did that well enough that I have not re-visited the Sulastics. That said, I would like to try them sometime.

The anti-sway bars made a *huge* difference in that "well, there goes everything off the shelves" effect that you get when coming off something like a driveway apron with the rear wheels coming off at slightly different times (like when you are turning out of the driveway). Before it would rock back and forth and try to whip everything around in the back. Now, with the bars, drama free. Plus the much improved cornering (which again, has to do with lean in a way).

BG

PS: Yes, running correct tire pressure can help the ride in general. That's step one. Along those lines, a friend just got stuck on the beach in his pickup (I was riding along) and when I asked it turned out he had like 80psi in the rear tires (2WD). This for a 3500# rear axle. Kinda hard to get out when you have pizza cutters for rear wheels!

[pdemarest]

Hey Blue - I don't really understand how the Shulastic things work but have read some good reviews by people who had installed them on pickup trucks. I have an aftermarket sway bar that a previous owner added but have no idea what brand/size it is (of course, I could get under the rig with a flashlight to check but its been raining here for days). I found that running a lower tire pressure had the most effect for softening the ride. If I won the lottery I would swap out the stock suspension for air bags. Loved the ride they gave me in my Navigator but ultimately after 170k plus miles and already having replaced the two front air bags and then having one rear fail I decided it was time to punt and replace the bags with traditional coil-over struts. Ride is much harsher now so I'm running my tires at 5 lbs. less pressure than before.

[Blue~Go]

The Sulastic shackles look to basically do what More-Rydes do, which is soften the shackle attachment, which I think just softens the "hop" or "harsh" up and down movement of the leafs. So I don't think they'd do the same thing as the anti-sway bars (which are more of a lateral effect).

That said, obviously suspension components all work together and there is some overlap. For example, when I put on a super beefy rear anti-sway bar, the harsh hopping was magnified (and the lateral stability was fantastic). I dialed back the bar to a thinner one and hit a happy medium though (but would still be interested to try the Sulastics).

[caconcourse]

The Sulastic shackles look to basically do what More-Rydes do, which is soften the shackle attachment, which I think just softens the "hop" or "harsh" up and down movement of the leafs. So I don't think they'd do the same thing as the anti-sway bars (which are more of a lateral effect).

That said, obviously suspension components all work together and there is some overlap. For example, when I put on a super beefy rear anti-sway bar, the harsh hopping was magnified (and the lateral stability was fantastic). I dialed back the bar to a thinner one and hit a happy medium though (but would still be interested to try the Sulastics).

You may not be aware of it but the MorRyde system includes an anti-sway bar between the spring holders, so it address both up and down and lateral issues. It is just a straight rod, but I guess the rubber provides the left and right damping action, as well as up and down.