Coil Springs

[Guest]

Hello, looking for some suggestions on where to get coil springs for my 73 Centurion.

Thanks

[Guest]

By the way, I would prefer it to be lower than stock. It actually has powder coated springs that look brand new in the rear but they are much higher than stock and I want to get rid of them.

[NTX5467]

You might contact Eaton Spring. They have original factory blueprints of factory springs back to the very early days of vehicles. THEN, you can use the "time honored" art of heating the coils to let the car's ride height drop or cutting the ends of the springs to achieve the same result. Only thing is that with either method, there is no way to return the altered springs to their original height.

ALSO, as you lower the ride height on the suspension, you also decrease the amount of wheel travel in the suspension too. As the spring is shortened, it also becomes a little stiffer, but not enough to keep the suspension from bottoming out on the rubber suspension bumpers sooner than it currently does or would with stock ride height. That will probably be tolerable on smooth roads at "town" speeds, but on not-so-smooth roads, the greater bottoming out of the suspension will transfer all of those "crash throughs" to the chassis and body, putting more bending stresses on those components. End result, more body shakes and rattles--among other things.

I seriously doubt you'll find any ready made lowering springs from the popular spring vendors, so finding someone that can competently heat or cut coils will be necessary--and they can quickly ruin a spring (that you'll have to pay for when you buy another) if they don't do it right the first time. Obviously, the springs on the rear of the car are not correct for it as someone else might have tried something and discovered it would not work as their "advisor" said it would. From reading a suspension thread at GSPerformance.com recently, it appears that there are some problems with the popular aftermarket spring vendors on some later model applications (they don't work like they are supposed to or have poor durability).

I wish you well in your project, but you could do a lot worse than putting it back "stock"--and spend more money in the process.

Enjoy!

NTX5467

[68 lesabre4dr]

try this site --------------www.espo.com ------------- good luck ! bruce

[KAD36]

I had a set made by Coil Spring Specialties in St. Marys, Kansas. They matched up my front springs and made a custom set of rear springs for me as I wanted the rear of my Buick to sit about 1/2 inch higher than stock. They had all the original factory spring specs. Reasonable price, all 4 springs matched up right, quick turnaround, lots of help on the phone, everything worked as promised first time.

Heres the address:

Coil Spring Specialties

632 West Bertrand

St. Marys, KS 66536

USA

TEL: (913)437-2025

Good luck.

[our51super]

I'm gonna add one more recommendation along with Ken's for Coil Spring Specialties. The price was right and the fit was fantastic. The car sat nice and level and rides great. Hey Ken, I noticed that you're an AE also ... these old cars and our passion for aero stuff must run together huh?

Cheers!

[Guest]

Don't use a torch to lower the springs. Ever. If you heat spring steel to make it move, you're changing the physical properties of the steel, etc., etc. Basically, you'll be making junk. Give Eaton a call, or that other company previously listed, and they will be able to make custom springs with the same spring rate, coil diameter, etc., but lower for you.

Though I don't remember what the rear springs of my '72 Centurion from my youth looked like, if they're tapered (smaller diameter circles at the top or bottom), you won't be able to cut any coils out. With the front springs, since they're the same diameter top to bottom, you could use a chop saw and cut coils off. If you choose this, start by cutting half a coil, install it, check height, then remove/cut as necessary until you get the desired ride height. There are too many variables such as vehicle weight, spring rate, engine, etc. to have a hard and fast rule as to how many removed coils equals a specific change in height.

Also, know that cutting coils will make the springs exponentially stiffer--the more coils you remove, the stiffer the spring. But again, if I remember correctly, my '72's ride was pretty soft and a little stiffer ride wouldn't have hurt it! When I had the car (at 16), I wanted to lower it about two inches, and I always hated how tall the windshield posts looked. I think the car would look great with the back of the roof left alone, but cut about 2-3 inches out of those windshield posts and give the roof an angle chop. It's definately improve the proportions of the car. I'll have one again some day, but the next one will be a convertible. But I digress.

As for bottoming out, it depends how far you lower it. 2-3 inches shouldn't hurt it. I've lowered a '54 3 inches and never bottomed, ever. I also lowered my Dodge truck 2-front/4 rear, and it never bottomed either, unless I hit a dip that was really severe, and the one I'm thinking of taxed the bump stops at stock height anyway. You might need to get shorger shocks. To do this, jack the car up off the ground and measure the suspeension travel at "full droop." Then put it back on the ground and measure the suspension travel at full compression (like when you'd go over a bump--have to eye-ball it most likely). Then get the phone number for a shock absorber company from the local autoparts store (it should be on the boxes), and call the shock manufacturer's tech line with those dimensions, the vehicle weight, and the fastener type (bayonette at one end, eye at the other or both ends are eyes, etc.), and they'll be able to tell you what existing shock you can use for your application. For example, I've got '89 Chevy S-10 4x4 front shocks on the back of my '56 Chevy.

Anyway, one last thing: I've seen some fresh Eaton springs that were much higher than they were supposed to be after they were installed. The company claimed the springs have to "settle," but these didn't and had to be sent back for the correct ones. If yours turn out to be too high, you'll need to send them back. Just thought I'd pass that on so you don't get discouraged if it happens to you. In each case, the second set of springs was right on.

Have fun!

-Brad

Oh yeah, this is critical: get yourself a good coil spring compressor. Snap-on and Mac sell them for less than $45, and it's well worth the safety investment. If you try to remove those springs without one (particularly the fronts), they're still under pressure and can shoot out of the spring pocket with the force of a cannon--not something you want your ribs or noggin to be in front of. Or your little helper's.

[Guest]

Thanks for your suggestions. This is a brand new hobby for me. I've never rebuilt a car before. I'm glad people like you take the time to respond and help a beginner out. Hopefully, someday I will be able to do the same. I just got my 73 Service manual yesterday and I've got a lot of reading to do. I just finished redoing the frame with POR-15. I'm going to give each of those companies a call. Thanks again. Brian

[NTX5467]

Thanks for adding the note about using a quality coil spring compressor, Brad.

With all due respect, Brad, "torching" coil springs to lower the cars was the time honored method before car enthusiasts knew what chop saws were. It was very common in the '50s and '60s when low ride heights were very common on "custom" cars--when if you went through a dip too fast, when the car rose up as it exited the springs could fall out on the ground.

As for changing the metal characteristics by heating the coils, if you go to a spring shop where they make their own springs, especially leaf springs which can also need rearching, the first thing they do is put the spring\stock in a kiln and then extract them (with proper tongs and such) when the metal is red hot and soft and workable. The leaf spring is then placed on a curved tool to which the red hot metal is beaten with a hammer so it will follow the contour of the tool and have the necessary arch to it. During this forming time, the metal will slightly air cool and a scale can form on the outside surface, which is knocked off by the hammer before the spring is chilled in a vat of water. I suspect that coil springs are manufactured similarly.

The metal in the spring is a special "spring steel" that will tolerate heat and flexing when cooled too. If heating the coils to lower the cars of yore made the spring more brittle and more prone to failure, everyone would not have been doing it back then. Also, in the absence of the high tech saws in those earlier decades, the springs typically were cut off with torches too.

Granted, cutting the ends of the coils would be the preferred method, but as you mentioned it is also a "cut and try" situation too. Not many people wanted to do that when just heating a short section of the spring to let it ease down would to the same thing. Cutting would also be more consistent side to side, but a "pro" with the torch could work the same magic with much less work involved. Not everyone had spring compressors back then either.

Previously, I mentioned the "bottoming out" as an awareness issue. Typical vehicles of the '60s and such had a total suspension travel of about 6 inches, meaning 3 inches in compression and 3 inches in extention. Therefore, if you take 2 inches out of the ride height, that would basically leave 1 inch before you hit the bumpers in that direction. Even if the springs got stiffer when shorter, 1 inch of remaining wheel travel before the lower control arm bumper hits the crossmember (with stock bumpers) is not a lot, but keeping the vehicle from bottoming out is also a function of the shock absorber control too. This is the advantage of using "drop spindles" on vehicles (when available) in that they retain full suspension travel and factory alignment while moving the wheel bearing mounting location to allow the lower ride height.

As for shock absorbers, unless you modify or shorten the suspension bumpers on the lower control arms in an effort to keep suspension travel with the lowered ride height, the bumpers should stop the suspension travel before the innards of the shocks stop it instead. Except in some of the new Monroe shocks, all shocks have the same valving characteristics throughout their full stroke.

I know that many people like the lowered "in the weeds" look, but there are also some compromises involved in using a vehicle with those modifications--expecially in the area of the rear bumper or exhauast pipes contacting the roadway on driveway approaches and such. It might be a "cool look", no doubt, but having to modidfy your driving habits might be an unexpected downside. And that is the big variable--where you live, the roads you drive on, and how they will interact with decreased suspension compression travel.

Personally, I like firm suspensions with full wheel travel as I always don't drive on really smooth roads (asphalt or otherwise) at posted speeds and I know that although my '77 Camaro is a little lower to the ground and has less wheel travel in the front suspension (at factory specs) than my '68 LeSabre or other American cars, I can easily drive over more different terrains in those cars than my Camaro any time I want to. As the Ford guys say, "No Boundaries".

Just some additional thoughts and observations . . .

NTX5467

[Guest]

Though I wasn't around then, I've talked to and work with a lot of guys who were--it wasn't uncommon to for cars to be lopsided because one spring got a little hotter and dropped more!

The thing with a torch is that it only affects a small, localized area, which will affect the temper, and it's getting so hot that the spring compresses in a localized area. At the spring shops, they control the rate of heating, cooling and they quench it--it's all pretty controlled, so the temper isn't affected.

Cutting the end of the spring off with a torch, if there's any damage, it's only at the very end.

It can be done with a torch, for sure, but there are much better, more modern methods.

We'll disagree on the lowered ride height . It's not perfect, and there are some trade-offs, for sure. But an inch or two isn't that big of a deal. My wife's '93 Chrysler Concord is also lowered 1.5-inches, and has 17-inch billet rims with Toyo tires. It looks great, and it's never bottomed out or scraped a driveway. The only place we have a problem is over the huge speed bump at the little league park.

Unscientifically, I've noticed that new, modern cars can generally be dropped 1.5 inches for a better look and maintain driveability. Older cars seem to go 2, maybe three. My '54 still has a TON of travel, and it's lowered three inches.

You are correct in that the rubber bump stops might need to be trimmed a bit. But again, these are pretty healthy and cutting a bit off them shouldn't hurt.

Brian--if you can, a "variable rate spring" is the best to order. It will be shorter, it will compress "softly" to a point, then it gets much stiffer as it compresses past that point. These are great for lowered cars, and it's what modern cars come with to strike a balance between comfortable road driving and performance driving. Inquire about them.

Enjoy!

-Brad

[BamaWildcat]

Hey Guys, if you are trying to get in touch with Coil Spring Specialties their area code has changed. New number with area code is (785) 437-2025.

[Guest]

I just ordered front and rear springs that are 2" below stock. Great price and delivery time. Thanks for the info.

[Guest]

And now there's more to the story. I just called up Coil Spring Specialties to check on my order and they haven't even started them. At first they couldn't even find my order. It's been two weeks already. Not too bad if they didn't tell me they would ship in 5 days. Then they ask me if I want the rear 2" drop like the front and that's what was holding the order up. So why didn't you call to double check even though I already told you that twice. Once on the initial quote and once on the order. So my intial 5-7 days to my door is going to be 6 weeks by the time it's all done. What really bugs me is I didn't even get a "sorry we messed up". And I'm so polite on the phone it would probably sicken you. Just figured I'd share that.