'55 Cadillac front coil springs

[njones]

Can anyone tell me the correct uncompressed height ( coils out of car ) for front coils on a '55 Coupe DeVille? I have a set of new coils which I think are correct but want to double check the height before installing.

Thx, 

Nigel Jones, Canada

[Otto Skorzeny]

I don't think you're going to be able to get a satisfactory answer to that question.

First of all, the uncompressed height of a spring is basically meaningless with the exception that it must not fall out of it's perches when the suspension is fully extended.

You could have two springs that have the same uncompressed height and squeeze one with your bare hands until all the coils are touching and another that might only compress an inch or two under the weight of a freight train.

What is important is the amount of force required to compress a spring to a specified height. I don't know if that data exists in your shop manual. Probably not. When I purchased new coil springs for my '56 CDV (or any other giant old car) I ordered the heaviest duty ones available and hope for the best. I order the heavy duty ones because these old cars are so heavy, they need all the help they can get.

The new ones were actually shorter than the 50 year old originals but what did that mean? Without subjecting them both to engineering studies on a hydraulic press to determine the amount of force required to compress each one by a specified amount, I just had to assume that whoever is making the new ones knows what he's doing.

They work fine btw.

Anyway, I know that's not the answer you wanted. If you can find the specs for the originals, put the ones in question in a press and compare. You may just have to install them and see how the car sits.

You could probably call Kanter and have them measure a set for you if you're sure the ones you have are brand new. That might put your mind at ease but it really wouldn't tell you if the two sets are the same.

[Dave Shepherd]

Otto, excellent reply, the metallurgy and design of the spring can vary the free height, the specs will really call for lbs/in of compression which of course will increase as the spring in squeezed down.  I bought a set of springs for a 55 Chrysler that I was restoring in my shop, and  I could not get them installed because of the free heighjt, sent them back and wound up with the same problem 2cnd time.

[Otto Skorzeny]

Hi Dave,

Were the springs for the Chrysler too tall to be installed? Couldn't you use a spring compressor on them to get them in?

[35-709]

FWIW  The new springs I bought and installed in my '60 Coupe sometime ago were slightly shorter than the originals, but also the material used was slightly larger in diameter.  I was worried about the new ones because my car was already sagging, turns out the new springs brought the car back up and the ride was great.

[Dave Shepherd]

Hi Dave,

Were the springs for the Chrysler too tall to be installed? Couldn't you use a spring compressor on them to get them in?

Yes I used a spring compressor and even with that they would barely fit between the lower arm and upper pocket, then they were  at too severe an angle to get the lower arm in the correct position to reinstall.  I wound up making up two thicker upper and lower insulators and this leveled the car with the oe springs..

[Otto Skorzeny]

Those springs were obviously made incorrectly or were for the wrong car. That's a growing problem with all of this aftermarket, reproduction stuff. A lot of this stuff is made who-knows-where and to unknown standards.

Restoring a car today is now a hit or miss proposition when it comes to using new parts. One never really knows if they are equivalent to the OEM parts but unfortunately in many cases there are no other options.

[Nigel Jones]

Well Guys I installed one of the springs and even with the compressor was almost an impossible job to get in. Obviously too tall. Once in the suspension had virtually no give even with all my weight on it, not good! The spring material diameter is the same as the originals ( which I unfortunately tossed ) but the height was different.

In the manual the spring installation is done by simply placing the coil in place in the upper pocket and then raising the A arm, not possible with my springs due to the  height and the weight of the car not sufficient to compress them.

The manual calls for a spring rated at 2410 lbs. but only gives the correct car height with the springs installed, no compression rating.

At this point I can go one of two ways, 10 cut the springs down and try again, here I would need to know the uncompressed height, or try again and buy another pair but could end up with the same problem.

I have a quote from Coil Spring Specialties who claim they manufacture to OEM specs, anyone have any experience with them?

Thx for the feedback,

NJ

[Otto Skorzeny]

Sounds like your springs came from the same place as Dave's. What does the company you bought them from say about them?

[Dave Shepherd]

For the record my springs were Kanters.

[Otto Skorzeny]

I kind of figured that. Kanter has a long history of supplying top quality parts with customer service to match.

Several years ago they had to recall and then stopped selling brake drums for various mid 50s Cadillacs. They were made in China and were the wrong size. In a phone conversation they told me they were having problems with the manufacturers quality, etc. and hoped to have the problems resolved soon.

I am personally aware of quality problems with their rocker arms and some pushrods.  I had my original rockers rebuilt rather than use the inferior ones supplied by them.

These problems are not limited to Kanter but are indeed finding their way to other suppliers as well. So many things these days are made in China, Vietnam, or who knows where and are of unknown or dubious quality, we can just use them and hope for the best. Short of making our own parts, I don't know what we can do.

BTW, I just bought a new radiator for my '79 Ford truck. The box said it was made in Thailand!  Thailand?! What the...!

Upon inspection and subsequent installation, I found that it is at least as good as the original in quality and superior to the original in design. (slightly taller filler neck and longer lower outlet with a crimped bead to keep the hose from being pushed on too far).

You just never know.

[Nigel Jones]

Sounds like your springs came from the same place as Dave's. What does the company you bought them from say about them?

Springs came from NAPA, mexican manufacture, can't return them as I didn't get around to trying them for over a year.  After some further research believe they are the wrong spring and out of a '66. Correct rating and size , just too long, hence the question on how much to cut off.

NJ

[The Tassie Devil(le)]

Probably better off selling what you have, and buying the correct pair?

Bruce.

[Otto Skorzeny]

Yes. I wouldn't cut them. I think you would just be setting yourself up for more aggravation.

Springs usually have the tops and bottoms slightly flattened to fit in their perches and sometimes have a tighter twist on the ends. The final coil is often a little more closely wound as well.

Maybe they'd take them back with the exchange for new ones? If not, sell them on ebay or something and buy the correct ones.

[njones]

Thx for all the feedback, will probably go ahead and purchase another pair.

NJ

[Warren Rauch]

  I would agree with the others here ,but mostly because it won't work to cut them off.  I could not find Cadillac numbers so Moog ones will have to do. The loading rate (spring constant) for 1955 springs is 424( pounds per inch of compression?) for heavy Duty and 391 for standard . For 1966 the rates are 364 HD and 321 STD.  For your information the nominal lenght for 55 is 16.284Hd and 16.377 STD , their HD spring is shorter because of the higher spring constant. The 1966 springs being 1.5 inches longer have a higher rated load when compressed to the 10.000 inch working size all these cars use.So if you could get them in they would likely work ,but have a softer ride.Warren