After some spring measuring... possible cheap rear lift springs!

[Sycho15]

Over on the ORC SWB Jeep BBS someone was looking for some real long leaf springs to use for more flex.

We found out that J-Trucks have 56" long SOA leafs...
We found out that Comanche's have 57" long SUA leafs...

Which got me to thinking. The SUA will have more arch to them, and with a little mixing and matching you could get the desired spring rate (stock MJ packs are 230#/ft) with probably ~4" of lift to boot.

There are about a half-dozen MJs in just two junkyards around here. Only 1 J-10...

[Rogue]

sweet...i may have found a cheap way to convert to HEI still a little more research to do...and when I get a chance to get some NAPA #'s hopefully a cheap high torque mini starter also...
smile.gif
thanks for the info and keeping this site great ;)

[bwright]

Let us know how it works out if you try it. What is the stock Wagoneer rear spring rate?

[scotty]

im confused. my 85 GW rear spring is about 56" long,and i always thot the j trucks used a longer one? :confused:

[Sycho15]

I'm pretty sure they all used identicle springs. AMC was great about getting maximum interchange-ability.

I've done an HEI swap to a 6-cyl before. Very easy and straight-forward. What do you need to know about it?

[sandmanb]

the springs on the j-trucks are the same as the wags and cherokee's. at least from 74 and up.

[bwright]

What is the distance from the spring eye to the pin on the Comanchee rear springs?

[Sycho15]

Let me grab a tape-measurer and check real quick...

Well I set the end of the tape about half-way between the U-bolts and measured to the front of the spring. It was about 25". Then I measured the same way to the rear of the spring and got about 32". These are approximate since I'm laying on my back under the truck, mucking around and not holding the tape perfectly still.

Good question to ask, I never knew how off-centered those springs are before.

[bwright]

From what I can find G.W. rear springs are 57" long, measure 26" from front of the spring to locating pin and 31" from locating pin to rear of spring.

Therefore, going by Sycho15's MJ spring dimensions, Comanche (MJ) rear springs swapped to the rear of a G.W. will move the axle forward 1" and provide about a 4" lift.

[Bluto74]

could you turn them around and gain one lenght?

[shambone]

I would like my axle back one inch, instead of forword. Makes room for cut-outs!!

[Gwamp]

This is pretty interesting. Who is gonna be the victim and try them out first? Are you sure they will fit 74-75? Those years still have the post mount in the rear instead of the newer style

[Dive 30]

Will J-2000 or 3000 springs bolt onto a G-Wag so you could have the stiffer, more load bearing springs?

Phil

[Sycho15]

I thought the post mount has more to do with the shackle than the springs. The springs still have eyes on both ends, right? I'm guessing the post-mount rigs just used shorter springs, which leaves me with the question, if you want to use longer springs, why not move the post?

[kidatforty]

I know my 69 has larger eyes at the front so wouldn't it be wise to keep it that way? I would think that it is important for stability. (less twist)

[Stolen76]

btt... very interesting

[LaJ10]

If anyone trys this please keep us informed.

[Sycho15]

I don't know about different eye diameters and all that, but running leaves forwards or backwards doesn't seem to make much of a difference. The CJ and YJ crowd like to run SJ front springs in the rear of their vehichles, turned around backwards to provide 2" more wheel-base. YJs can also run them up front to gain another 2" of wheel-base.

[HeepofaJeep]

if you want to use longer springs, why not move the post?

Those posts are set into the frame FOR GOOD! The only way to move them would be to cut them off and then build yourself new spring hangars. In building the hangar you would lose strength because the shackle sticks out about an inch from the frame. It would be easier to move the shackles underneath the frame and get newer axles.

[BIGYELLOW78J10]

Originally posted by Sycho15:
I don't know about different eye diameters and all that, but running leaves forwards or backwards doesn't seem to make much of a difference. The CJ and YJ crowd like to run SJ front springs in the rear of their vehichles, turned around backwards to provide 2" more wheel-base. YJs can also run them up front to gain another 2" of wheel-base.By being turned around, the Larger eye is still the frame mounted end, and the small eye is in the shackle. I think having the large eye in the frame mount is the only safe way to go.

Daniel

[Rande]

The early J2000 and such springs may be a different width. Its been a while since I had my J4000 but as I recall, the front springs were 2" wide and the the later J10-20 trucks front springs were 2 1/2" wide. Don't know about the rears though.

So, are the early rear springs the same width as the later ones?

[Sycho15]

Some of the YJs run Shackle-reversals with GW springs, some run shackl-reversals with regular springs, and they don't normally turn the springs around. I've just never met a spring that cared which way it was facing.

[bwright]

Well, I'm going to try it. So, if anyone around middle TN has a set of MJ rear springs for sell let me know - branwright@comcast.net

[Sycho15]

Yeah! We've got a test subject! Ashame you're not closer to here, there are plenty of MJs in some local 'yards.

[4LoTJ]

By being turned around, the Larger eye is still the frame mounted end, and the small eye is in the shackle. I think having the large eye in the frame mount is the only safe way to go.
I've been running flipped Dodge Dakota springs in the rear of my TJ SOA for some time now without any issues. This rig takes a lot of abuse, but still gets drive safely on the highway.
http://www.pkulak.com/photos/albums/userpics/10011/normal_ic7w2270_std.jpg

[4LoTJ]

Wow, didn't realize how OLD that thread was before I posted!

I was searching for possible junkyard springs to replace the 4" add-a-leaf/block combo on the back of my 81 Chero. It sits a little low in the rear.

[ August 26, 2004, 02:39 PM: Message edited by: 4LoTJ ]

[FSJ Thing]

Originally posted by RogueStar:
sweet...i may have found a cheap way to convert to HEI still a little more research to do...and when I get a chance to get some NAPA #'s hopefully a cheap high torque mini starter also...
smile.gif
thanks for the info and keeping this site great ;) Keep us updated on this! I got a GM HEI off a mid 80s blazer for $10 and ground the crap out of it to go into my 360 when I had a Wag, but it wasn't worth the trouble. I love HEIs with the one wire hook up and being all self contained, so keep us informed!