Leaf Spring opinions

[ScrapIron]

I am working on the rear suspension on my 2005 Chinook again after being bad sick since last september, not covid related. I ordered the Sky Offroad shackle flip kit which arrived today but now i need some leaf springs.

I already finished the front end using a Dana 60 out of a 2005 F-350 Super duty 4x4. Everything on the front is brand new and ready to go. Now i need some nice leaf springs for the back to raise it. Currently it has air suspension on it which i will remove and replace with leaf springs.

I got a quote from Alcan springs of $1700 for the springs with a 6 to 7 week production time. Does anyone have opinions on the quality of their product or should i look at Deaver springs or atlas etc....?

My next thought is.... should i even use the shackle flip kit or should i just try to gain all the height i need with the springs, or considering the weight of this truck, would i be better off utilizing the shackle flip kit in combination with a spring with less arch in order to avoid potential spring sag?

Originally this truck came with springs from ford with very little arch to them at all. Ford part number 5C2Z-5560-VA. The truck is quite heavy at 11640 pounds with 7840 pounds of that being on the drive axle.

By the way, i ordered the Sky shackle flip RAW steel. The reason is because everytime i order and pay extra for powder coating its never done correctly and the powder coat starts to crack and fall off in short order and then of course the parts begin to rust. I decided powder coating is a waste of money and i would do better to prep the parts and spray them with paint myself.

 

[carringb]

I would use either the shackle kit with stock springs (maybe add a leaf at most), or taller springs without the shackle kit. If you try to combine both, the driveline angle will be way off. Even with the stock springs the shackle kit might put the angle off just enough to cause vibration. If that's the case, the fix is super easy... just add some caster alignment shims from an F650 front axle.

What kind of air system do you have now? And why do you want to remove it?

 

[ScrapIron]

I would use either the shackle kit with stock springs (maybe add a leaf at most), or taller springs without the shackle kit. If you try to combine both, the driveline angle will be way off. Even with the stock springs the shackle kit might put the angle off just enough to cause vibration. If that's the case, the fix is super easy... just add some caster alignment shims from an F650 front axle.

What kind of air system do you have now? And why do you want to remove it?

Its not a matter of wanting to scrap the air system. Its more a matter of i installed a dana 60 under the front of the truck and it has raised the truck beyond what the air system can compensate or be adjusted for. I could remanufacture all of the brackets and make it work, i just dont want to.

Its the Reyco/Granning RD800F system.

https://reycogranning.com/suspensions/model-rd800f/

 

[ScrapIron]

Here is the system on my truck. Note that it utilizes an S spring in unison with an air spring. Not unlike the shackle flip kit, when you over extend the air bags it cause the S spring to rotate at it mount point on the forward frame rail effectively changing pinion angle as well as moving the axle forward slightly.

I could keep it like i stated and rebuild all of the brackets including the front frame rail brackets. I just dont want to, i want to switch to leaf springs so i have little to no maintenance or worry about rear suspension components. Im sure running just leaf springs will degrade my ride quality, but thats a sacrafice i am willing to make. Air suspension is not a maintenance free system.

Im lost on the F650 caster shims youre mentioning. Are they for the rear axle?
My front suspension utilizes 4 link radius arms and they are adjustable so adjusting caster on the front of the truck is a breeze.

 

[ScrapIron]

Is this image what youre referencing? Item number #5336?

 

[carringb]

Correct. The F650 alignment shims (5336) are likely needed on the back axle, if you use the shackle flip kit, in order to maintain an in-spec pinion angle.

 

[Lilnuts2]

Scrapiron, the first thing I would do go to a scale with your rig loaded how you use it. Get a separate front and rear axle weight. Park on level ground and measure your existing pinion angle. Then measure the elevations of your spring mounting points and your axle spring pad. Determine how much lift you want. With that info any spring shop can build you exactly the springs you want. Don't get caught up with all the name brand spring shops there are a lot of good ones you don't hear about.
If you do need to adjust your pinion angle you can buy tapered shims with any degree you need to get the corrected angle.
Like what carringb mentioned.

 

[motovan_mn]

I got a quote from Alcan springs of $1700 for the springs with a 6 to 7 week production time. Does anyone have opinions on the quality of their product or should i look at Deaver springs or atlas etc....?

For what it's worth, Ujoint Offroad switched to using Alcan springs for all of their mail-order shipments. They still use Atlas for their in-house builds. I think it was mostly a matter Atlas not being able to keep up with their demand, but it shows that Chris thinks highly of Alcan!

I believe Justin at UJOR CO is also running Alcan springs on his personal van, though I'm not positive.

 

[ScrapIron]

Just tried mowing the lawn and now im sick after 15 minutes. Not sure im going to be able to finish this project.

 

[carringb]

Another idea…. What about adding a 2” lift block under the Reyco-Granning leaf, and swapping in 2” taller airbags?

Seems like you have such a nice suspension now, you’d be going backwards going to leafs.

 

[REF]

Good idea, I’d suggest the same, far easier and much cheaper and quicker to get things buttoned up, I know most of these air bag co’s have optional lift brackets available, some are universal…..but things seem to have taken a turn for the worse going by his last post.
Also curious if there has been any issues with the current air bag system to warrant not wanting to deal with it.
……Hope you’re ok, sounds like you gotta stay away from mowing the lawn!

 

[WillTheThri11]

from a purely physics standpoint a shackle flip is less stable. I'd tend to avoid it on a heavy rig that I was going to do long trips with. I don't have much experience to back that up and don't know of anyone who's done them on E-series but a bunch of people tried them on Toyotas and reported that it didn't feel safe...not sure if that's a vehicle specific thing.

 

[ScrapIron]

Another idea…. What about adding a 2” lift block under the Reyco-Granning leaf, and swapping in 2” taller airbags?

Seems like you have such a nice suspension now, you’d be going backwards going to leafs.

It already has blocks thicker than 2 inches, plus spacers on the S springs. Again as i stated, in order to raise the truck any further will require building all new brackets including the front frame rail brackets. Adding taller bags alone isnt an option because it causes the very same issues as a shackle flip. To compound the problem further, i had to install a track bar on the rear to control tailwag in gusty winds at hiway speeds, such as passing a semi truck etc.... That said, a shackle flip isnt going to cause any issues that the truck didnt already experience with this air bag system.

If you look at the picture i posted of the air system in one of my first posts here...You will note rub blocks on the side of the frame rails. Those white rub blocks combined with the ear sticking up from the axle U-bolt brackets are all that keep the axle centered under the truck. Raising it any further is simply not an option because those ears would no longer be making contact with the rubbing blocks. The system is not designed or intended to be used on a lifted truck.

That means the trackbar would also have to be refabricated. Reyco does not offer optional brackets for their kits. I wont even get into the air bags, i tried finding some taller bags a couple of years back when i had the weldtec kit on front. Lets just say it was an exercise in futility, firestone and Reyco were zero help. Thats when the blocks went in. I managed to raise it a couple of inches but also had to buy and install a trac bar to help stabilize the rear tailwag.

Attached is the picture of the rubbing blocks and ears. As you can see theres an entire pandora's box of issues that have to be addressed to make this system function properly on a lifted truck. Its simply not something i care to mess with. Its a nice setup on a non-lifted truck, but its simply not intended for a lifted truck. Its great for hauling loads and towing etc... because it keeps the truck level regardless of weight, but its really not intended for offroad applications on a lifted truck. Then of course there are the droop straps on each side which are the green things you see on each side of the rubbing block.

 

[arctictraveller]

I have Alcan springs on the front and back of my E250. They were made by the former owner though so I have no real experience with the new owners, but........ After weighing the van fully loaded I had the rears designed to eliminate the 4inch lift blocks and ended up about the same height as before, but without the blocks. I wanted a more progressive spring and ended up with eight leaves, and it was a noticeable improvement in ride quality. I installed those at a buddy's shop, then drove two and a half days to Alcans shop so I could have him measure for the new springs I wanted in the front, and to make sure the ride height was correct. Unfortunately, it ended up about an inch and a half higher than the back. Long story short, he was never willing to fix it and I discovered that he was selling the business at that exact same time, so I ended up adding spacers in the rear to get the van nearly level. Never the less, I have no experience with their new springs, but would assume they would be fine. The lesson for me is that building springs is not an exact science despite shops using soft ware to design them to the desired specifications. So, I'd recommend being very clear on what you hope to accomplish and asking if they will correct them if they miss the first time. I'm guessing the chances are good you will be fine.

 

[ScrapIron]

Arctic, I installed the front axle using brand new Ford OEM springs, Ford got the part number off of the trucks build sheet. Once i finished installing the dana60 under the front it sat way higher than i was expecting. However any amount of lift in the front would exceed the rears ability to level the truck because i already had the rear maxed out before i started. LOL

I sent Alcan my truck make, model,the cat scale print out with the drive axle weight and the steer axle weight as well as the Ford OEM leaf spring part number. I then told him i would like to raise the truck 6 inches from where it sat in stock form. He seemed confident that it isnt an issue. What i am concerned about is spring sag. Obviously to gain that much arch in a spring they will have to use longer spring sections and then bend them to create the lift/arch. As the spring begin to sag it flattens out which pushes the shackles backwards. If the springs flatten out to much it could potentially create an issue with the shackle actually hitting my black water tank. Im wondering if i should tell them i want 7 inches of lift beyond stock since i know they are going to sag at least some once the weight of the truck is on them.

My only other option is the Skys offroad kit and stock springs combined with a rear trac bar to stabalize the side to side motion i will get from the shackle flip. Originally the truck came with that MORYDE leaf spring system which utilizes big rubber blocks on each side to help cushion the ride. I still have all of that stuff which i removed to install the air suspension, but it is also limited in regards to lifting the truck.

 

[arctictraveller]

As the spring begin to sag it flattens out which pushes the shackles backwards. If the springs flatten out to much it could potentially create an issue with the shackle actually hitting my black water tank. Im wondering if i should tell them i want 7 inches of lift beyond stock since i know they are going to sag at least some once the weight of the truck is on them..

They calculate the amount of lift using the fully loaded weight, meaning that once installed and on the ground, you should end up with what ever the desired lift was. They use a computer program to calculate the size and number of leaf's based on what ever parameters you give them, but that doesn't mean its an exact science. Springs do sag over time though, but it normally takes years for them to settle, so compensating for that now may give you a bigger lift than you want. Additionally, your bump stop should be designed to stop the spring from flexing enough that the shackle contacts the fuel tank, or over compress the shocks. Also, once they do sag, you can have them re-arched back to the original shape, just make sure they do a hot re-arch where they re-heatreat the metal not just bend it.

 

[ScrapIron]

Arctic, ok, thanks for your information and input. I know you had some issues when you were doing your springs. I recall reading your posts back then. We had a conversation about installing a trac bar on the vans to help resolve tailwag on lifted vans back around that same time.

 

[1pharmer]

My E350 came with 4 rear leaf springs per side. I found 5 rear leaf springs at Pic N Pul on
an Econoline. This corrected the problem.