Leaf spring re-arching.

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probably pretty close to level.I think a stock 67 - 69 dart with 14" tires would be 21 1/2" at the highest point on the rear wheel well.
The higher the the front end the more caster you lose
 
cuda620 said:
How much lift did the ss springs give you and how unlevel was it? Thanks
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I took about 70lbs in the air shocks to get it the way I wanted and had a rough ride and the front eye bushings were sloppy too. This is it now with just super stock springs and regular shocks and the ride is a lot better. I have lowered the front end around an inch since this picture was taken to give it a smoother ride in the front and make up for taking the weight off the front with aluminum heads and radiator
IMG_1552.JPG
 
Mattax said:
Height of the body over the rear axle depends on the vehicle weight, the weight distribution, and to a lesser degree the front ride height setting.
That's why Chrysler and many different stock leaf spring packs. They also tried to account for use, building in more rate, and/or ratio for cargo or torque resistance on some.

To get some idea of the selection of factory replacement springs without going through the parts books, you can just skim the offerings from Stanley Spring (Harrisburg Pa) being sold here
Dodge Lancer Dart and Swinger Leaf Springs - Stengel Bros Inc.
Plymouth Valiant Leaf Springs - Stengel Bros Inc.

The only rear height info I've seen from the factory is at Hamtramck Historical.
The 1970 Hamtramck Registry "Chrysler Passenger Car Bumper Heights 1965 thru 1976" Page
Not really sure the intended purpose of this document as these heights were never in service manuals, possibly for final check before or after delivery to dealers. Note on page two that these specs are for fully loaded cars (5 passengers, full fuel) but does not say what options. Also the bumpers are somewhat adjustable and the body has some uh slop so this isn't quite the same as suspension service reference.

Chrysler set the cars up so the leaf springs are nearly flat at normal loads. This is for handling as explained in Chrysler literature such as here. That said, springs will show the effects of over a million cycles. I figure 70-90K miles is a good average for typically used vehicle (occassionally fully loaded, some bad roads, etc). Sometimes they will be fine for longer, and under real abuse, less miles than that.
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I found this in a different thread, and went to look at the Lancer Dart and Swinger leaf springs. That is of course the measurements of a totally unloaded spring, out of the car.

Then, the 1970 Hamtramck Registry I found rather difficult. The height is measured under the middle of the front and rear bumpers at the lowest point and down to the road surface, but with 5 people in, and full of oils, water. But, the rear bumper on the '65 Dart goes up in the middle. So, is it meant a line you can imagine or is it meant to be measured where it goes up too. The Hamtramck registry says 13,2 inches in front, and my car is about there empty, with no people in. Then it says 15 inches in the rear, and my car is 16.5 inches if I do not measure where the bumper goes up, and that is also empty. I mean, no passengers in it. And, I have no idea what kind of weight a passenger is supposed to have.


Bill
 
ir3333 said:
probably pretty close to level.I think a stock 67 - 69 dart with 14" tires would be 21 1/2" at the highest point on the rear wheel well.
The higher the the front end the more caster you lose
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Not to argue, but actually the front end height has very little to do with caster. However, the height of the rear affects caster a good bit. Caster is the forward or rearward tilt of the steering axis when viewed from the side of the car. So you can see, the height of the rear would much more greatly affect caster than the front. This is why when you jack a car way up in the rear, you normally lose some high speed road stability, because it reduces caster.
 
Bills65Dart said:
Well, you more or less ask the question I was going to ask next, does anyone know the ride height in the back of a '65 Dart 4 door sedan ? Or, if I adjust the front to the specified level, should the car be level, leaning a bit back, or should it lean forward, in other words be higher in the back than in the front ? Now talking about how it was out of the doors in 1965.


Bill
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IKn the FSM has height measurements of the springs themselves, believe it is the arch height.
 
take a closer look Rusty.If you lower the front upper control arm to raise the front end it will shift the top ball joint forward giving the imaginary spindle a more vertical position.
 
Bills65Dart said:
I found this in a different thread, and went to look at the Lancer Dart and Swinger leaf springs. That is of course the measurements of a totally unloaded spring, out of the car.
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Correct.
You can use those measurements from Stengel (Stanley Spring) to get the arch loaded if you know the weight on the springs.
@autoxcuda and I concluded they are using the term spring capacity to indicate load that will bring the arch to zero.
Don't think I called them to confirm that but it cross referenced with some info we had on a few specific spring packs.
upload_2019-9-6_9-21-28.png


pass.jpg


We can also calculate the spring rates.
The standard leaf springs have a spring rate around 85 lbs/in (530 divided by 6.25), & (620 / 7.125)
and the Heavy 6 springs have a rate around 114 lb/in (600/5.25)

If you can drive the car up on a scale, and then pull forward so the rear wheels alone are on the scale, you'll know approximately the weight on the springs. You'll haveto estimate the axle wieght.
Or, if you have the springs off the car, you can apply weight and measure how far they move. If you do this by standing on them, have something to hold on to when getting on and off. ;)

As far as the heights in the HH archives documents, maybe @Alaskan_TA will know more about the measuring points.
The five passengers etc should bring the car close to maximum weight allowed. That will be in the owners manual and shop manual.
 
ir3333 said:
take a closer look Rusty.If you lower the front upper control arm to raise the front end it will shift the top ball joint forward giving the imaginary spindle a more vertical position.
Click to expand...

I didn't say the front had no effect. I don't have to take another look. I was an alignment and suspension tech foe a very long time. The rear has much more effect on caster than the front.
 
70 DUSTER CRATE said:
General Spring in Kansas City !
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Still in business? Man they got me out if a jam on a Friday afternoon when a front spring broke on my Peterbilt....I was going to load some parts for the power plant in Vero Beach, FL after a hurricane. Two hours and $300 later I was rolling!
 
BTW...most new raw spring steel and finished replacement springs come from India.

20 years ago I visited a well known spring seller in Detroit. They advertised that they sold "custom" springs for every application. The joint was really just a warehouse with one corner devoted to assembling some orders.
 
my mopar A body circle track springs were made in Mexico.Each pack was test ground for quality and the test marks are obvious.Our local truck repair spring specialist told me they were high quality springs and if he re-arched them they would remain were he re shapes them.
They have a 320 ton press and will re-arch them assembled or individually if you like.
 
I have tried to find 1095 quality bar stock, no luck. What I find is for making knives, so it is just small pieces. Not like 2.5" wide and 5 feet long. And most of it is ground flat, and I just need regular rolled and annealed.

I can get it from the local spring shop here in the city, but they want like over $250 for a whole spring for my car if it has 5/8" bolt, and $350 for it if it has 1/2" bolt because that was so rare, and for leaf material for one side, another $200. So, that was not even interesting looking at.

Doesn't anyone in the entire nation sell spring material for a decent "fee", and in the quality and size that is needed for a car spring ? Do the companies who make car springs have some kind of monopoly on spring material ?


Bill
 
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