Spring length, arch and leaf number

I've searched here and elsewhere on the web with little satisfaction . . . I hope someone here has these stats.

Does anyone know the length and width of stock Jeep leaf springs, the amount of lift that they provide (lets say arch) and the number of leafs. I was wondering about waggie's and Jeep trucks as well.

My reasons are both selfish (my '73 has a home grown shackle reversal with non-standard length springs and I'd like to replace the springs) and academic.

I know that the early jeeps had more leaves and were narrow and the late ones were wide and had fewer leaves but how did the length and arch change with different models?

Thanks for your information and experience!

 

For my cj5 1974 they are 39 3/4" X 1 3/4" front and 46" X 1 3/4" rear with 7 leafs std or 10 leafs opt in front and 5 std or 10 leaf opt in the read . Will get my fsm out and check arch later. This is 74 cj5, I hope this helps

 

Believe me, I am no expert on this subject. You may wait for (jeepen nerd) to respond he seems to have the technical information. But on my 1955 Cj5
the spring packs don't only have more leaves, but they are also wider than my 1963 that I know is stock.
Doug/Tucson

 

R)

 

Along these lines, another bit of information that may be helpful to others is the distance between the shackle mount and spring mount (measured at the frame, not the springs). This came up for me since I'm changing my Willys MB springs to longer Early CJ5 springs. So this information was needed to relocate all of the mounts. greencj5 gave me some measurements from his Jeeps of:
38.5" front
44.75" rear.

Again this is center of eye at shackle mount on frame to center of eye at spring
mount on frame, not the length of the leaf spring.

 

Thanks Sparky, I have to admit I missed the technical page on springs . . . I searched the forums but neglected the most important spot.

The frame shackle eye to eye measurement is a good one to have and if others will add then to this list it would be great!

The springs on my Jeep are ~46 inches eye to eye (but my jeep is currently up on stands). But again, the PO custom fabricated the suspension and I have no idea where the springs are from.

Thanks again to all who contribute info.

 

Alright most all of this info is out of the "jeep performance handbook" by Jim Allen. (highly suggest buying this book, some of it is a little cheesy but there is def. some real good info in it)

If you need to know any Jeep spring rates they are in the book also, or ask here and I'll look it up, just tell me the year and vehicle.

To figure the amount of lift that you will aquire you need to know your spring rate of the springs and the sprung weight on the front axle/rear axle. Once you have those numbers, subtract the weight of everything bolted below the springs, axles, wheels, tires from the front/rear weight totals. Sample frotn weight is 2000#, axles,wheels,tires weigh 400# so your sprung weight would be 1600#. Divide that number by two since half the weigh will be on each spring, 800#s per spring. Once you have that divide the sprung weight by the spring rate. So a stock 55-65 CJ5 spring rate in the front is 240, this sample would give you 800/240 3.33" of spring deflection. Now once you have this number you can subtract it from the arch of the spring and that will show how much lift you will actually have with the weight of the vehicle on it. So if with stock springs you were at 1" of deflection these springs here would give you aproximatley 2"-2.5" of lift over the existing springs.

I used these calculations to figure out my stuff on goldmemeber and they all came out exactly how I wanted. I ended up with right at 4.5" of spring deflection, which with stock XJ/YJ springs makes them almoist flat but they have a little arch still left to them. Which in turn keeps the center of gravity down low and allows the springs to have more down travel offroad rather than alot of upward travel, or making the vehicle sit taller than desired.

 

usefull stuff

 

The springs on my Beastie right now don't seem to have any deflection at all. They are REALLY stiff! Ten leafs on the rear, the pack is just a hair over 3 inches thick. It's like riding with the axles mounted directly on the frame.R) :hurrican:

 

Mine was just like this before I swapped the springs out for 4wd.com 2.5 lift springs. At least now I can push the front of the Jeep down and it moves

High5

 

On my m38a1, there are 12 pack military springs front and rear. Actually, they may be 14, but I think they are 12. The frame flexes before the springs do. They are rusted up though and they have to be rusted together. I mean this is ridiculous. I'm gonna break them apart and grease between the springs hopefully in a few months. I want it street legal first, then I'll take care of these secondary issues. I know most people with military springs swap them out right away. If worst comes to worst, I think I can just pull some leafs out.

 

I was wondering if pulling some leaves out would cause safety problems.

Actually I want to lower mine... the rear bumper sit 24" off the ground, and the door rim height is 29". For short legged people (both me and the wife) it is difficult to get into, although putting in the roll cage helps some cause now there is something to grab onto. I've got 12" of clearance between the top of the tire and the bottom of the wheel well opening. Don't think I need that much.
Putting the 30x9.5x15's on doesn't change that but an inch or so and they don't even come close to rubbing.

I've been considering removing 4 leafs from the bottom, and placing them over the main leaf to lower the tail by bringing the axle higher by an inch and a bit.
Dumb idea?:?

 

You could install a step.
You could put a block spacer between the axle and the leaf springs to lower it.

 

I was going to use the removed springs (to soften the springs some) as the block, which should spread some of the load out a bit. :hurrican:

 

And the steps, though I am not looking forward to pulling the gastank. :hurrican:

 

1960, did you try the spring modification? Sounds like it might be a good idea. It should lower it, softern it, but probably keep the axle wrap at bay. That's kinda how race truck leaf springs are set up.

 

Pulling and changing leave is very common. My Flatfender was riding very rough (old school lift) and I pulled 2 of the 5 leaves, this helped but didn't lower it much. Once springs are pulled other issues pop up, a big one is spring wrap. Depending on the pack, this might not be a problem but a traction bar of some sort might be needed. The back half of leaves may be cut too, this would act as a "slapper bar" and help with spring wrap. Then there are small things like spring pins, make sure you have some, shackle angle will change because the spring will be longer with more squish.

How long are your shackles? Believe 3"ish is stock, the Jeep can be lowered a 1/2" for every inch the shackle is shortened.

Since you are running such small tires, might want to look at stock springs or a quality aftermarket springs, maybe custom. I'm guessing with 12" of clearance, there has to be a lift and it might be the old school "stiffer is better".

I'm not a big fan of blocks and probably won't move leaves on top of the main. The back will work but the front, steering stresses really make them a no no.

 

Behold! The Necromancer has arrived to resurrect this thread!

I guess the /tech section is long gone? (Beyond even my powers of resurrection...)

 

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