Rear Leaf Spring mod with Durango Springs

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derrangedgadgeteer

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Well alrighty, It's been a while since I posted about any work on the dartness, and I've been finagling with this and that, fighting with carburetors, putting in new shocks. But the one thing this car's needed since I got it, has been stiffer springs. It loves to bottom out over everything. It rides over bumps like they were waves on the ocean. and the body roll is ridiculous. Don't even get me started on loading it down with heavy stuff.

I don't, however, have enough money for replacement springs. new or used. I did however, have money to go to the junkyard. So I took some measurements, and went looking. Lo and behold, there sat a 2002 Dodge durango, with the back wheels already off. and the leaf springs of the right width, very close to the same length, and what looked like a similar forward bias as my dart's springs. So, $60 and some cursing later they were mine.

And just today I got to put them on. Now, they're not a bolt- in deal. Not by a long shot. So after alot of thinking and asking around, I decided to pull the lower leaves off of the old stock springs, and replace them with the beefier lower leaves of the durango springs.

Here's how I did it:

MVI_1447.jpg

Just your run-of-the-mill 7 3/4 rear under a '75 dart. Note the rustiness of everything under here.

First: I jacked up the back of the car as high as I could. Put it on stands, chocked the wheels, etc.

Second: Undid the shock absorbers, pushed them out of the way.

Third: Removed the four Axle U-bolts. This is a pain in the hindquarters, as there were no threads on the bolts to speak of, just a bunch of rust I had to plow the nuts through. It took time, elbow grease, anf a big wrench, and it fought me all the way. I even ended up breaking one of the u-bolts. After removing them you can remove the tie plates to reveal...

Fourth: ...The spring pack stud thingies. I guess it's kind of a bolt, and kind of a stud, whatever. but it's pictured here.
MVI_1454.jpg

(note axle tube, break backing plate, etc.)

Now, on my axle for some reason, there's an interference fit between the pad that rests on the leaf springs, and the opposite end of that stud, and so the nut can be removed without taking the axle loose. which greatly simplified this project.

Fifth: Take a decent c-clamp, and clamp down on the leaf spring approximately as shown. This provides a measure of safety for when you take that nut loose.
MVI_1465.jpg

This is a good time also, to take those clips off the leaf springs. I'm not sure what they're properly called. I've heard them called stabilizers, I've heard them called spring clips. I dunno. but this is what they look like:
MVI_1461.jpg

Now, I don't know what condition yours will be in, but mine crumbled as I took them apart. and I'll have to find or make a suitable replacement soon. yours might survive to be reused. Perhaps, but I wouldn't count on it.

Once you have removed the nut, you can back off the clamp, and the spring pack will gradually come apart, and you'll then be able to remove all the leaves except for the top leaf. (The top leaf is the one that matters, since it puts the diff where it needs to be, and at the angle it needs to be.)

Sixth: Now, you want to take the durango springs apart this same way, however, when taking the stud loose you'll need to put vise grips on the one rounded end of the stud. otherwise you won't be able to get the nut off. IMPORTANT!!!! Make sure you keep the leaves and everything in between the leaves where they were when you take the spring pack apart, or else you'll have squeaky springs that may fail prematurely.

Seventh: Now, set aside the top and bottom leaves of the durango spring packs. you won't be needing them. The stud for the A-body spring pack will not be long enough to accommodate any more than those three leaves.

Eighth: Line up the holes of all your new leaves, and I recommend putting a screwdriver or a drift or something through them to make sure they stay aligned as you put them on. Also note the bias of the springs. The hole should be closer to one end than the other on each and every leaf. The shorter end should point to the front of the car and vice versa.

MVI_1466.jpg


Ninth: touch the tip of your aligning tool to the stud, and slide them over the stud. You might want a buddy to hold them in place while you grab your clamp, and clamp the springs as shown. Once you have some tension on them with the clamp, your buddy can let go, and then you simply cinch down the clamp to compress the springs. Once compressed, there should be enough stud to thread the nut back on it, and you'll want to tighten this down too.

Tenth: Once the nut is snug, you can remove the clamp, And start putting your u-bolts and tie plates back on. Remember when I said I broke one of the u-bolts trying to get the rusted on nuts off? Well nobody anywhere near me carries direct replacement axle u-bolts. So, I went hunting for something close. I discovered that at my local Northern Tool & Equipment they had a perfect fit u-bolt in their trailer section. It even came in a kit.

The Brand is "Ultra-Tow" It's an Axle tie plate kit for 2 3/8" Round tube axles. Comes with 4 u-bolts, 8 nuts, and 2 trailer tie plates (which I'm not going to use) The UPC for it is: 8162856116 And here's a link: http://www.northerntool.com/shop/tools/product_200514156_200514156 It ran me about $20.
MVI_1467.jpg

Anywho, you put in the factory tie plates (you can toss or keep the ones that come with the kit, but you won't need it for this project) Just like they came out. (except with the new hardware of course.) I torqued the bolts to about "HNNnnngh" foot-pounds. How many is "HNNnnngh" foot pounds you ask? I dunno, but I'm fairly strong, and it's a big ratchet so somewhere around 100 I guess.

Eleventh:
MVI_1468.jpg

Put the shocks back in place, drop it, and see how you like it.

MVI_1469.jpg


This spring mod works out to about 2.5-3" of lift over my old worn out springs. (for reference, with 195/70/14's on the back, the fender was just below the edge of the wheel rim before I started.) And the ride is significantly firmer, but it is not at all unpleasant. Bumps, even large ones are barely felt now, the car handles immensely better, It's much more confident in the turns, and you break traction before body roll becomes excessive. :toothy8:

I checked the pinion angle as best I could with the car on the ground. and it was very close. I'm going to let the suspension settle and check it again, but according to some of my friends, it's plenty close enough that I won't have problems. :dontknow:

I do think this looks a bit silly, especially with those tiny tires, but that's a price I'm willing to pay for better ride, better handling, and goddamnit, I don't bottom out over speed bumps anymore. :glasses7:
 
Very cool write-up, way to be resourceful :glasses7: This would work on my '70 Duster but I'm probably going all-new with the rear springs when I swap to an 8 3/4".

Do you happen to know if those Durango leaves will fit on a Jeep Cherokee XJ? I have a '93 with 200k+ miles and the rear end sags a bit, would be great to have an extra 2" or so (lol that came out wrong :blackeye:)
 
That gives me some hope...I just bought a used set of super stock springs from a local guy and it turns out that the main spring of one of them is broken. I wonder if I could used the main spring from my old set with the other leafs from the ss set to fix the issue. The guy who sold the springs will not refund my money. Hmmmm..worth a try I guess. Just have to get a set of the spring clamps.."stabilizers".
 
DUDE! Your killing me here with laughter and joy !!!!

ACE job, well done!!!!:prayer:

Now, to find you bigger tires!
 
I did nearly the same thing as you. I junked out a couple of A bodies, mostly for front disk parts. I tore down the springs, and the springs under my 67. I simply put the longest leaves of both original spring packs from the junker and the 67 back in the pack. I believe I have one more leaf than stock, but they are all the longer leafs. The thing sits just right. I hope to get the disk brake front end under it soon, which will also mean AT LEAST a front sway bar. I may have "enough stuff" to manufacture mounts for rear bar as well.
 
Very cool write-up, way to be resourceful :glasses7: This would work on my '70 Duster but I'm probably going all-new with the rear springs when I swap to an 8 3/4".

Do you happen to know if those Durango leaves will fit on a Jeep Cherokee XJ? I have a '93 with 200k+ miles and the rear end sags a bit, would be great to have an extra 2" or so (lol that came out wrong :blackeye:)

Well first, even if you wanted to do this swap you'd need different u-bolts than I used for an 8 3/4, I doubt an 8 3/4 has 2 3/8 axletubes.

For a jeep I don't know. The thing that will make the biggest difference, is if the factory springs have a front or rear bias like the Durango leaves do. I don't know what Jeeps do, but if they don't have any bias, putting those leaves on will put more spring tension either to the front or back of the axle, and it'll mess up your pinion angle. I don't know by how much. I know the bias on the durango springs was a little different than the bias on my a-body springs, but it didn't mess up my pinion angle appreciably.:-k

furydan said:
That gives me some hope...I just bought a used set of super stock springs from a local guy and it turns out that the main spring of one of them is broken. I wonder if I could used the main spring from my old set with the other leafs from the ss set to fix the issue. The guy who sold the springs will not refund my money. Hmmmm..worth a try I guess. Just have to get a set of the spring clamps.."stabilizers".

Well, one thing with superstock springs, which I was looking into before going into this. the main leaf on them is longer than the factory a-body spring, so putting the spring pack under the factory top leaf will greately ease installation, since you won't have to weld in new spring shackle mounts.

only thing to keep in mind, with the super stockers being five leaves on the driver side, and eight on the other, you'll need to replace the spring pack studs with longer ones to accommodate the extra leaves. I was originally planning to do this, actually, until I discovered I could get the nut off without having to take the axle loose and putting pliers on the other end of it. I was going to replace them with grade 8 allen head cap screws.
 
Well I did some more research on this, turns out adding leaves from other Dodge/Jeep trucks is a fairly common "low-buck" trick for adding a couple inches of lift to an XJ Cherokee; Dakotas work as well as a few other models, just have to check to make sure the bias is close like you said.

Also after some more thought I think I will do the same swap you did for my Duster, no sense spending $250 on new springs when I can get the same results for 1/4 that price. That leaves extra money to put towards new rear wheels and Bilstein shocks all around :evil1: ... I can also test-fit leaves with my current axle to see how much lift I get out of them before I swap in the 8 3/4".
 
The stud/ bolt "thingie" is called a "spring center bolt." You can buy them at "real" parts stores, or even in a city the likes of Spokane, which has a spring shop

Also, you can buy "spring clips" from such places

like these:

Just clamp the leaves, put them on and clamp them, and hammer/ bend the ears down over the sides of the other piece

bt70kc.jpg


On my car, I junked a couple of Duster/ Demons and ended up taking two spring packs apart, IE my original, and one from one of the junkers on each side, and put the longest leafs of both packs back in. I believe I ended up with one more leaf than stock, but they are longer leafs, and it really stiffened up the car. Sits just about where I want it now

15n7g39.jpg
 
Nice job. Might even warrant a sticky. This is an example of what I consider the best of FABO. Creative solutions that don't break the bank.
 
Hey not to dig up an old thread but I recently completed this mod on my '70 Duster and it worked as intended. I went to a local junkyard specializing in older car parts and picked out a pair of leaf spring packs with the same dimensions as mine (20x35") but visibly thicker. I swapped the lower leaves onto the main in my car and voila! Instant 2" lift just like I wanted... however it still seems a bit on the soft side, after I swap the 8 3/4" rear in with tires and wheels to match the front (275/60R15 on Rallyes) I may cut the main leaf of the 'new' springs and add it to the pack as well. Still a big improvement from before though, I could finally get new shocks for the back because the exhaust pipes were no longer rubbing them from the sagging springs lol.

Before:

579238_10200141555233861_392374792_n.jpg



After:

305910_10200141556073882_422662460_n.jpg
 
I wonder if this will work for an early A. My 65 Dart convertible had some kind of helper springs mated with the shocks so I imagine the original springs were shot. I'll have to look into this.
 
I wonder if this will work for an early A. My 65 Dart convertible had some kind of helper springs mated with the shocks so I imagine the original springs were shot. I'll have to look into this.

Dartman et me know if this will work on your early A I'm having the same prob

Great post man loved it
 
I wonder if this will work for an early A. My 65 Dart convertible had some kind of helper springs mated with the shocks so I imagine the original springs were shot. I'll have to look into this.

Dartman et me know if this will work on your early A I'm having the same prob

Great post man loved it
 
I don't see why it wouldn't work, just measure your stock springs and try to find a set that matches like I did... leaf springs are leaf springs after all lol
 
I don't see why it wouldn't work, just measure your stock springs and try to find a set that matches like I did... leaf springs are leaf springs after all lol

^^^ x2 There's no reason it wouldn't. Just get some springs and try it. Worst comes to worst, you can put the old ones back on.

Thanks y'all for the support, this mod has worked great for me. The car settled down a bit from where you see it in the pic, but it still has a nice rake to it.

Also, The car does really well loaded down. I took it across the scales at my local scrapyard just for giggles one day and it weighed in right at 3800lbs with me, my tools and some random junk in it. It rides happily and handles very well like that too. I recently also hauled an all-iron 318 long block in it (along with the usual stuff, putting my estimated weight at 4300lbs) there was little increase in the body roll, though the car sure felt heavier. The extra 500lbs didn't even squat the back end though, It just put it down to about stock ride height.

With the success of this mod, I may consider pursuing a similar mod for the front end. notching and boxing the upper control arms and installing coilover shocks in place of the stock shocks, but retaining the t-bars. (universal coil overs don't cost a fifth what new t-bars do.) But that I'll save for another thread, if I do it. Its going to get an alignment, I'll talk about it with my suspension guy.

Oh, and Thanks 67Dart273, "Spring center bolt"and "spring clips" got it.
 
On a side note, us XJ Jeep guys have been doing this mod for years, with great success... best doners for the XJ so far seem to be mid-'90s S-10 2wd pickups... it's basically the same idea, but we take the S-10 main leaf and cut the spring eyes off, round the cut edge some, and sandwich it in right under the Cherokee main leaf... usually nets about 3-4", and retains stock ride quality... aftermarket lift springs are usually much higher spring rate, and are pretty stiff, sometimes ending up too harsh for a daily driver... those in the know call this an add-a-leaf (AAL)...

Nice job!
 
I done a similar job to my Duster. The donor car was an '88 Gran Fury cop car. I added one leaf, one of the longer ones.
I also added the rear sway bar. Since I had never driven the Duster before all this work I can't comment on how much lift or improvement it made.
C
 
If you want to firm up the front to match the rear get the KYB gas adjust shocks. I put these shocks in front and rear and it was anight and day difference. Went from mushy to firm just like that.
 
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