Need shorter leaf springs for my 1988 D60. Ford leaf spring bible?

[rebar]

After my 2500 mile round trip to colorado (15k GCWR) , Iv determined my cummins rebuild is a success. 80 mph, 2300 rpm, 850 egt, 14 psi, 14 mpg.



Now I feel this project deserves the 4x4 conversion.. I have a 1988 ford D60 and understand no kits exist for its installation into my 95 E350. Im now searching for the leaf springs which were not included in the D60 purchase. From what Iv been told on the kingpin spring lengths (27.6" front spring eye to center pin. 28.1" center pin to rear spring eye) The forward 27.6" front spring eye to center pin length is to long. It locates the front spring eye forward of the front bumper 2" after I added 2" of wheel base for 34" tires.

Can anyone tell me if shorter springs are available for my axle or spring interchangeability? Or recommend a company who can build the springs I need? I cant seem to find a ford leaf spring bible as a reference..

Thanks!

 

[justcuz]

Measure your spring pad width. I'm pretty sure they used 3" wide springs in front by 88. Ford started using 3" wide rear springs in F150s in 1973 I believe. There is an online spring chart I have downloaded in my old computer and I'm sure it is still out there. You could probably get away with 2.5" wide springs with shouldered urethane bushings like the use in square body Chevy lift kits. I'll see if I can find a link to the leaf spring chart.
Edit: leaf spring comparison chart on Pirate 4x4 by Mr N. 1973-79 F100/150 4x4 did have 3" wide rear springs. 55" long, front half is 24" long, rear is 31" long. They came in 3 weight ratings from 1650 to 2450 I believe.
There are Chevy, Ford, Dodge and Jeep springs all listed by overall length, width and measurements before and after the center pin.
I would check frame width measurements and compare them to an F350. If they are the same or close you could use the spring brackets off of maybe a Superduty or an Excursion. I bet you could find Ford brackets that would rear mount the shackles and solid mount the front spring eyes to the front end of the chassis.

 

[why3zx]

Do you have a build thread for the cummins conversion?

 

[rebar]

Thanks justcuz

The kingpin pad width is 3". The leaf spring brackets need to be custom made as I doubt any stock parts lines up. But the 55" long, front half 24" long you mentioned sounds like it would work well. Why rear springs though? And assuming the weight rating is for one leaf spring. What rating should I be looking for if the front of my van weighs 3600#?

Is this the chart by Mr N?

I have allot to learn about suspension in general, and now second guessing my leaf sprung axle choice. Do you have any links for a basic suspension education?

Do you have a build thread for the cummins conversion?

Sorry No. I do have some pictures of the engine rebuild though.

 

[BajaSportsmobile]

You are going about this all wrong - don't look for factory springs from another application that will sorta work.

Figure out where you want your axle located in your wheel well opening (clue, push it forward of center for tire clearance) as well as ride height and then go talk to a good spring shop in your area to get some ideas.

 

[rebar]

You are going about this all wrong - don't look for factory springs from another application that will sorta work.

Figure out where you want your axle located in your wheel well opening (clue, push it forward of center for tire clearance) as well as ride height and then go talk to a good spring shop in your area to get some ideas.

Thanks. stock wheel center to front of frame is 26.2" , but I need to find measurements for the kingpin.

 

[justcuz]

Yes that is the chart.
The springs are rated for capacity per spring, so with the weight of your Cummins you need to support that.
Also what BajaSportsmobile said, with leaf springs that have rear shackles the axle will move back as the spring compresses. Your tire should be set up in the wheelwell to allow this.
Alcan Springs I believe is in Colorado. Any good spring shop can build you custom springs.
I suggested the Ford springs because;
1. They would work.
2. It sounded like you wanted DIY solutions to springs.
3. It is very cost effective to use existing springs.
4. I'm frugal and use a lot of wrecking yard parts on my stuff.
With your twin I beam your dust cap center will pretty much be the end of the spindle, as far as the king pin inclination, it will be slightly inclined rearward for good caster angles.
The bolt through the center of the spring is called the center pin.
There are spring/suspension calculators out there online. You first need to know your total vehicle weight and the weight of each axle. You should do this weight with the vehicle set up for a trip, loaded and ready to go. Then do your springs based on that weight.

 

[rebar]

That spring chart in the link doesn't have 1 ton springs.

I called a local spring shop and turns out the measurements I had were wrong. The front 88 F350 3" spring length is 23 7/8. Back 28 3/8 with 3" arch and 2200# rating. So those will work fine.

So its just a matter if I buy new springs for $250 each or junk yard pair for $100.

Rockauto has better prices. But not sure why they list multiple weight ratings for the same 1988 7.3 F350.

 

[justcuz]

The multiple spring ratings are for different GVW ratings.
There is a Ford Excursion Forum that has a list of F250/350 springs that can be used to lift Excursions using factory truck springs.

 

[rebar]

Thanks

I learned the stock 88 F350 front springs were 2200 lb capacity.

 

[BajaSportsmobile]

I called a local spring shop and turns out the measurements I had were wrong. The front 88 F350 3" spring length is 23 7/8. Back 28 3/8 with 3" arch and 2200# rating.

Why do you care what an F series pickup truck's spring length is - you have a E series van and it does not have a F series frame or spring mounts? Leaf sprung 4x4 vans ride like crap with short truck springs. Look at how hard Ujoint has worked to get a leaf sprung van to ride as good as they can. They have changed spring specs several times and would never have been satisfied with F series truck springs. If you are going to make this mistake at least learn from what others have done. Ujoint doesn't make a spring hanger for your van, but that doesn't mean you can't learn from what they do.

 

[rebar]

If you are going to make this mistake at least learn from what others have done. Ujoint doesn't make a spring hanger for your van, but that doesn't mean you can't learn from what they do.

No one has give me any install info, or what not to do, other than "don't install anything other than what I sell." And now " Leaf sprung 4x4 vans ride like crap with short truck springs."
I guess I could go searching archives on how he built his springs. But wouldn't it be a little forthcoming to offer the info? I guess that would take more than a couple seconds though.

Even tried to buy them.. "There are too many variables". Please..

 

[Bikersmurf]

The point Agile was trying to make is Ujoint has found longer springs are needed to make Vans ride well. Even though he doesn't make a kit for your year, I'd try to Benifit from his experience. I've read his Vans ride very well. For ride quality, longer = better.

I don't have a kit to sell you, but I'd recommend the flattest and longest springs you can fit under your rig. I'm sure Chris, or someone else, can give you specs for a Ujoint setup. I'd mimic his design, and build custom mounts to work with your frame and setup. I can't give you all the detail, but if you had the same springs, shocks, and steering geometry Chris has come up with to perfect his kit, you should end up with a comparable end result.

 

[BajaSportsmobile]

No one has give me any install info, or what not to do, other than "don't install anything other than what I sell." And now " Leaf sprung 4x4 vans ride like crap with short truck springs."
I guess I could go searching archives on how he built his springs. But wouldn't it be a little forthcoming to offer the info? I guess that would take more than a couple seconds though.

Even tried to buy them.. "There are too many variables". Please..

I don't have anything to sell you either. Just trying to help.

PM me your phone number and I would be glad to call you and help with anything I can. I've worked on and built a lot of 4X4 vans so I think I have something to offer - not sell.

 

[justcuz]

It would be interesting to see just how long a spring Chris is using. 56" is not short by any means for a front spring.
We all know a longer spring will be more flexible, but that flexibility can work against you too. You can have a spring that is long enough that axle forces will S bend the spring while trying to deliver power to the ground. Off set center pins can counter this force a little by having the shorter end of the spring resisting the forces that cause the S bend. There is a lot to know about springs, but they are not a total mystery. Lots of good info can be found for research purposes. Old Chevy Power Catalogues had chassis dynamics sections in the rear that talked about all kinds of suspensions and setups. Prepare to Win, by Carrol Smith is another good resource for suspension setups and chassis dynamics. Both these publications refer mostly to race cars, but the theory behind the chassis dynamics are relative to any vehicle and can be used in a truck, van or SUV.