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1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1969 Mustang => Topic started by: mbyers on March 18, 2024, 12:12:22 PM

Title: 1969 coil springs
Post by: mbyers on March 18, 2024, 12:12:22 PM
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
Title: Re: 1969 coil springs
Post by: Bob Gaines on March 18, 2024, 02:02:53 PM
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.
Title: Re: 1969 coil springs
Post by: Bob Gaines on March 18, 2024, 02:06:03 PM
Matt ,I should say that the forum stands ready to help with your restoration process questions.
Title: Re: 1969 coil springs
Post by: krelboyne on March 18, 2024, 03:50:23 PM
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/ (https://www.springsnthings.com/)
Title: Re: 1969 coil springs
Post by: RoyceP on March 18, 2024, 06:25:11 PM
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.
Title: Re: 1969 coil springs
Post by: jwc66k on March 18, 2024, 07:54:57 PM
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
Title: Re: 1969 coil springs
Post by: Bob Gaines on March 18, 2024, 08:41:35 PM
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/ (https://www.springsnthings.com/)
Some years yes but 69/70 Shelby springs are not Shelby specific.
Title: Re: 1969 coil springs
Post by: mbyers on March 19, 2024, 03:03:18 AM
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.
Title: Re: 1969 coil springs
Post by: RoyceP on March 20, 2024, 12:22:15 PM
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.
Title: Re: 1969 coil springs
Post by: jwc66k on March 20, 2024, 02:54:37 PM
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
Title: Re: 1969 coil springs
Post by: RoyceP on March 22, 2024, 06:51:07 PM
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.
Title: Re: 1969 coil springs
Post by: jwc66k on March 22, 2024, 07:10:43 PM
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
Title: Re: 1969 coil springs
Post by: RoyceP on March 23, 2024, 11:39:26 AM
Learning stuff does not mean you know anything. It just means someone taught you what to believe.
Title: Re: 1969 coil springs
Post by: midlife on March 23, 2024, 11:49:38 AM
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.
Title: Re: 1969 coil springs
Post by: jwc66k on March 23, 2024, 11:51:07 AM
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
Title: Re: 1969 coil springs
Post by: RoyceP on March 24, 2024, 02:57:39 PM
I typically have to re - arch rear leaf springs due to metal fatigue. I have never had to do anything to coil springs despite 200,000 or even 400,000 miles. They just do not wear at the same rate.


Rubber parts I had to replace the front stuff several times in the course of 400,000 miles. Idler arms last maybe 25K miles. Strud rod bushings maybe 50K miles. Lower control arm inners last maybe 30K miles.
Title: Re: 1969 coil springs
Post by: jwc66k on March 24, 2024, 03:20:45 PM
I typically have to re - arch rear leaf springs due to metal fatigue. I have never had to do anything to coil springs despite 200,000 or even 400,000 miles. They just do not wear at the same rate.
True, but they do compress from use, and the results from different manufacturing processes, where made and when can be a factor. They ain't identical or perfect, they just conform to a range "called a tolerance".
Jim