Topic: 1969 coil springs

[mbyers]

Hello
I?m in process of restoring 69 Gt 500 vert and presently working on front suspension. I need some help on finding correct coil springs. My car has A/C and it?s my understanding that cars w a/c need higher rated spring vs non-a/c cars. None of reputable parts suppliers etc Napa, Eaton, CJ pony, open tracker carry that specific spring. 67-68 have different springs for a/c vs non a/c cars. Has anyone on forum run into this problem and if so how did you rectify it or where did you find correct spring?
Thx for your time
Matt

[Bob Gaines]

Hello
I?m in process of restoring 69 Gt 500 vert and presently working on front suspension. I need some help on finding correct coil springs. My car has A/C and it?s my understanding that cars w a/c need higher rated spring vs non-a/c cars. None of reputable parts suppliers etc Napa, Eaton, CJ pony, open tracker carry that specific spring. 67-68 have different springs for a/c vs non a/c cars. Has anyone on forum run into this problem and if so how did you rectify it or where did you find correct spring?
Thx for your time
Matt

I feel that you are overthinking the problem. There certainly are different part numbers for different FE Mustang/Shelby spring applications . It has my experience that there is little difference in ride height and feel between the A/C and non A/C big block coil springs. There is a reason why there are not more spring rate alternatives that companies like Eaton (not the OEM mfg btw) provide . In fact I am wondering why you think that you need to replace the ones on the car now? I also think that there are going to be plenty more restoration originality issues that will be more visibly noticeable then the nuance detail that you are inquiring about.

[Bob Gaines]

Matt ,I should say that the forum stands ready to help with your restoration process questions.

[krelboyne]

If you must replace your front springs, you should talk to Laura at ESPO. Should be 428CJ Competition Handling, if not Shelby specific, with your assorted options.

https://www.springsnthings.com/

[RoyceP]

Typically front coil springs never wear out. If they are pitted replace them with originals that are not pitted. From my experience aftermarket coil springs are always too stiff and lift the front of the car too much.

[jwc66k]

From my experience aftermarket coil springs are always too stiff and lift the front of the car too much.

Partially true. It takes a while for new springs to "settle". (It took over a year on a 65 GT convertible to get close.) Another sales "scenario" is that aftermarket spring sellers "combine" a lower rated spring with a more heavy duty type for sales and inventory purposes. That was the explanation we got a few years back. Whether it's true or not, I don't know.
Jim

[Bob Gaines]

If you must replace your front springs, you should talk to Laura at ESPO. Should be 428CJ Competition Handling, if not Shelby specific, with your assorted options.

https://www.springsnthings.com/

Some years yes but 69/70 Shelby springs are not Shelby specific.

[mbyers]

It?s a valid point you make Bob. I?m a purist to the core, Sometimes I am my own worst enemy and tend to overthink things???case in point w this issue. I guess since there is only one OEM spring available for this model yr , I should have assumed it was indicated for all applications. Very appreciative of  everyone?s speedy response and expert advice. RoyceP comment quite interesting and wonder validity to his point. I just assumed 90k miles and sitting around for over 50 yrs carrying wt of BB would fatigue springs. What?s interesting is I would agree that ride height still looked factory. I think I will restore my originals and reinstall. Maybe replacing saddles, pair of quality shocks and ball joints is all I need?? I can always replace springs. Thanks again to everyone for help in finally resolving this issue for me?.. I beat myself up about it for months.

[RoyceP]

In my experience coil springs do not settle. There is no difference from the time you install them to any other time. Spring saddles wear out and the rest of the rubber parts do too.

[jwc66k]

In my experience coil springs do not settle. There is no difference from the time you install them to any other time. Spring saddles wear out and the rest of the rubber parts do too.

It's called "metal fatigue". It's there.
Jim

[RoyceP]

It's called "metal fatigue". It's there.
Jim

It's not something I have ever seen in 50 years of working on these cars. I have seen severely pitted coil springs fail and sag but never good ones.

[jwc66k]

It's not something I have ever seen in 50 years of working on these cars. I have seen severely pitted coil springs fail and sag but never good ones.

Springs distort under a continuous load, compression in this case. That's a fact. I learned that over 50 years ago in school. Again, it's called "metal fatigue". I saw some of it in real time on cars and trucks in the same time period you didn't.
Jim

[RoyceP]

Learning stuff does not mean you know anything. It just means someone taught you what to believe.

[midlife]

Metal fatigue is due to 2 basic factors: load and number of cycles.  Metal fatigue usually implies failure or imminent failure.  Before failure, the metal does become weaken and begins to yield.  Car springs must be designed for an incredibly large number of cycles to last 100k miles.  That said, if the car is a low mileage one, the metal fatigue should not be an issue; if the car has an awful lot of miles, the springs may be weakened.  This may explain the differences seen among the coil springs.

[jwc66k]

Learning stuff does not mean you know anything. It just means someone taught you what to believe.

It must have been enough to work for a couple of aerospace companies successfully designing and building "stuff".
Jim