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Build-your-own springs
https://slantsix.org/forum/viewtopic.php?f=13&t=29585
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Author:  NewSlanter [ Tue Jun 17, 2008 8:12 pm ]
Post subject:  Build-your-own springs

My rear springs are saggy. I have 5-leaf springs under my 1970 four-door Dart and they're pretty tired. About 3 months ago I got me an 8 1/4 rear with a set of springs on them. They're looking a bit on the rusty side, but I was thinking about putting together a 6-leaf pack to bring up my rear end. My questions are;

-How?
-Where do I get the bands that hold the springs together?
-Where and how many zincs should I put in?
-How do I guarantee the added leaves are properly aligned (front to back)?
-How are the bands tightened around the spring pack?

I'm not in a huge rush to get this done, but my car always looks like I'm coming hard off the line, even when I'm parked.

Thanks in advance,

Nat

Author:  SlantSixDan [ Tue Jun 17, 2008 8:15 pm ]
Post subject: 

H'mm. Me, I'd go to a spring shop and have the springs re-arched or replaced. I've never found pro spring service to be too expensive.

Author:  Sam Powell [ Wed Jun 18, 2008 5:49 am ]
Post subject: 

Your current springs are sagging mostly where the single top spring is unsupported by lower ones. This is between the end of the 2nd spring down and the shackle. You can easily assemble your own, custom spring pack. That is what I did on this car. I first puchased new springs. These sagged soon. I then had them re-arched by a spring service in Hagarstown Maryland. They sagged again. Then I fixed it myself by adding another, longer number two spring to the pack.

If your intention is to use the 8 3/4" rear. You might start with what you have there, if springs came with it. You will need to havea custom drive shaft made, which can be done at any really good truck service shop. There are several in my area which will splice the shaft, balance it, and install new U joints for around $125. They don;t charge huge fees for this because it is primarily a service for poor struggling truckers, and not rich kids looking to spend money on a car that already works fine.

If the set up you end up with is also sagging, you can install a longer 2nd spring in the pack, which supports the rear of the top spring better. Just keep the two sides even. I made my number two spring extend half way to the shackle from where it originally ended. I did this by taking a number one spring from a spare spring pack, and cutting the eye off, and then shortening i the rear to the desired length. You can do this with a hack saw.

I reused my original pack clamps, although you can find them somewhere online for sure. A good custom spring shop will likely sell them to you.

After doing this, my car sat too high in the rear. So, I purchased new (for the rear suspension) front leaf spring boxes from Mancini, which had a secondary set of holes to lower the car two inches. This put the car height just where I wanted it, as well as got the axle center in a better relationship to the front perch bolts.

None of this work is that hard to do. It is just blacksmith work. Get new Ubolts, and keep them lubed up as you work. The most difficult part of the job is getting the original bolts off. Simply cut them off with a hack saw. AFter you have the new ones on, they will be easy to remove and reinstall if you need to take them off a second or third time to adjust things.

Sam

Author:  NewSlanter [ Wed Jun 18, 2008 9:12 pm ]
Post subject: 

Sam,
Do you have any pictures of your set-up? How do you get the old clamps to fit the new, thicker spring pack?

The 8 1/4" rear is already under the dart. The springs looked a bit rusty, so I used the ones already in the car. The rusty ones are six-leaf jobbies, so I might compare the sets and see if I can find a leaf the right length. Do I need zinc inter-leaves? Can the springs be painted? What kind of paint?

Thanks,

Nat

Author:  Doc [ Thu Jun 19, 2008 10:58 am ]
Post subject: 

I have "rebuild" many leaf stacks over the years and it is not hard if you have a few extra leaf spring assemblies to use as parts and you have some big clamps to help hold things together as you work.

I re-use the zinc interleafs when I have them but cleaning and spray painting also works OK.

In general, I get the best handling when the front section of the stack is thick and solid (the "locating" section) and use the rear section of the spring to set the spring rate and vehicle height.
Having a near flat spring when installed and under nomal load is best for correct "rear steer" and traction geometry so don't get too much arch into them.
DD

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