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Discussion Starter · #1 ·
I'm restoring a CJ7. I want to replace the leaf springs. It had light duty springs on the front and rear (4 leaf front, 6 leaf rear). I was wondering if I should change to a heavy duty spring (6 leaf front, 9 leaf rear). If I do change will it how will it change the ride. Also any thoughts on a shackle reversal kit for the front?

Thanks!
 

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Welcome to the board! Since you're new here, we can't give you a good answer to those questions until we get some information from you about how you use your Jeep, praticularly how much off road use does it get, and on what kind of terrain.

Generally I don't think much of suspension modifications for CJs unless they are primarily an off-road vehicle, with little street use and very little highway use.

The primary value of heavy-duty springs is in carrying heavy loads. Unless you plow snow with it, or carry bricks, stick with the stock springs. They ride better and work better off road too.
 

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I just went through this two times, and I have two more to go...

You didn't say what year CJ-7 or what engine so the information below may not be correct, but for the most part it will be...

Current springs are 2" wide in the front, 2.5" wide in the back.

The CJ's are very front heavy, so heavy springs in the front.
The ass end of CJs is light, so stock springs are adequate unless you load it down and keep it loaded all the time.

Number of leaves doesn't indicate spring rate.
Front springs will normally settle out about 2" in the first year (especially with an I-6 or V-8, so don't be overly conservative in the front.

If you do a spring lift, do all 4 as an aftermarket set.

If you keep the Spring Under Axle configuration, if you use mostly flat springs a shackle reversal won't really help you.
Super soft rock crawler springs will have a problem with shackle reversal.

If you use stiff springs, lifted springs, or especially if you use stiff lifted springs and if a line between the spring 'Eyes' is going to be above the axle then a shackle reversal is going to help you considerably.

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You currently have a spring under axle configuration.
Do you plan on doing a spring over axle conversion?
If so, disregard following...

If you are going to do a spring over axle (SOA) with mostly stock, flat springs, the shackle reversal won't gain you much and may actually hurt steering.
This is more of a 'Crawler' thing than a trail and highway Jeep thing...
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There are some other things you should be aware of with a shackle reversal...

1. Relocation of shackle to the rear will entail boxing in the frame and inserting the upper shackle mount through the frame to keep any kind of pinion angle.
A bolt on kit that puts the shackle mount under the frame simply won't work, too hard on front drive line parts and screws up your steering geometry.

2. When springs compress, the axle moves forward.
That extends the drive shaft.

When you do a shackle reversal the drive shaft may be pushed backwards into (and sometimes through) the front of the transfer case.
Make sure you have enough 'Slide' in your drive shaft.
 

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[ QUOTE ]
The number of leaves in the back denote if it was sold for/with a hardtop, or not.

[/ QUOTE ]

There was also a heavy duty suspension option available without the hardtop.
 
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Discussion Starter · #6 ·
Welcome Scott...
A lot also depends on your mechanical skills....if you're not afraid to wrench, use a torch or chop saw, then there is a lot you can do.

I personally don't think a shackel reversal is worth the time or effort....it's a solution looking for a problem...if you have fresh rubber bushings then your jeep will drive fine...stay away from polly...highly over rated....

One option that is a total bolt on is to use stock Wrangler springs...including up front. They are the same width as the rear, but all you have to do is change out your front spring hanger....which is a weak point anyway. A stock rear hanger works fine...drill out the rivet up front and move the hanger forward 1" and bolt in place. You can now use stock rear shackles for the front. Then later, if you decide to go SOA, all your changing out now is spring perches and shock mounts.
 

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[ QUOTE ]

The CJ's are very front heavy

[/ QUOTE ]

My CJ7 was 300 pounds heavier in the front than the rear with hard top and doors on and an amc v8.
 

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Ok on that note I have an '80 CJ-7 with I4 and 90% street driving. It sets on 30x9.5, can I run 31x10.5 on the stock set-up? The reason I bought the jeep is that its the first that I ever drove that I liked...everything else was lifted (poorly). Thus I am very scared to lift it adn lose the ride that I enjoy...Just think it needs a little altidude adjustment.
 

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My '78 is not lifted and has 31-10.50 MTs. Off road the front tires rub the fender lip, and the backs touch the insides of the fender well. Neither is consequential, and I don't think the fronts touched before I took the sway bar off.
 
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Discussion Starter · #10 ·
To summerize all this.....
It is better to run tires up to 31" with a stock lift than to put a cheap lift on....wait until you have the bucks to do it right....and I don't consider 2" a viable option....why spend bucks for 2" when you will quickly realize you want more....it's a lot like tires...once you buy them, your stuck with em until they wear out....or you can find someone to buy them from you for a fraction of what you paid....

FYI...31" is a magic # in more ways than one way....when you go over 31", not only are you looking at lift, but new gears, different driveshaft, etc.

So...drive it with those 31" tires and stock springs....that looks a lot better than a hoky cheap lift....
 

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I let mine rub cause it takes the rust off, but you can't make that claim with a Stainless Steel body Jim!

There must be something under there you don't want us to see is the reason you won't lift it..../ubbthreads/images/graemlins/ooo.gif
 

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There must be something under there you don't want us to see is the reason you won't lift it....

[/ QUOTE ]

Nope. Except for the front 44, which is as close to the 30 as I could make it, it's all just the way it rolled out of Toledo. And I like it just the way it is. /ubbthreads/images/graemlins/grin.gif

I can go on off-camber places a lifted Jeep can't, and turn and squeeze through tight places a wide-axel rig can't go.
 

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I used to run 31" BFG AT on 15x7 on my stock cj (Still have the 5 tires and 5 rims, want them?) they were great for trails.

Now I did a SOA gaining 6.5" lift with stock '92 springs and a shackle reversal and it rides much better, a little springy, but with the sway bars on, just fine. Better road manners IMHO. 2" is just a waste of $$. Stay stock and save for everything else you will want. I geared up (2.73 - 4.56), and locked up (Auburn in the 20, T-Locker up front) and axled up (Warn Full-floaters on the 20) Before I spent the $$ lifting it, and adding 35" MTRs. Now I am set (If someone has the xtra d30 axle shafts I need for spares /ubbthreads/images/graemlins/smile.gif) to go, instead of big lift, big tires, no guts (gears) and open diff.
 
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