78 Vette Coil Springs & Liners

[Joseph A.]

Hi:

I'm just starting my reassembly of my off body restoration on my father's 78 Vette. I have a few questions about the spring force on the front coil springs and rear spring liners. The Vette has a L-48 Engine, Automatic Transmission, Air Conditioning, and does not have Gymkhana suspension. I have been looking in different catalogs (Ecklers, Corvette Centeral, Doctor Rebuild, and Zip). They pretty much all say 68-82 Small block 350 front Coil Springs. I thought there was differences between spring force for different year Corvettes. Also does anybody know where I can get a set of spring liners for my rear spring. I went to my local GM Dealer and we found out that base suspension is not available, but Gymkhana is. Also I talked to Bears Corvettes in Pennsylvania he told me that he does not stock them but he can get them. He told me that over the phone about a month ago. I went to a metal fabrication shop here in Virginia. They told me that the liners for the rear spring were made of a Zinc-based Alloy. Any help would be greatly appreciated.

Thanks

Joseph Adelizzi

[Patrick H.]

Re: 78 Vette Coil Springs & Liners

Joseph,

The correct spring liners and correct paint are available as a kit from Quanta, at http://www.quantaproducts.com
They were black plastic, not metal of any kind.

If you still have your original front springs and they are not crusted and rusted, then reuse them. Only one version is currently sold because it's not worth it for catalog dealers to stock (or spring people to regularly make) several versions of the front springs. I'm sure that Joe L can tell you if there is ANY chance your original springs are still GM-available; I doubt they are.

Since you're new at it, one tip: restoring or refurbishing your original parts "usually" is a much better idea than replacing parts "just because they are available" in reproduction form. Nothing will fit like your original part. Nothing. That's why the vast majority of us follow the #1 rule of old Corvette ownership: Don't EVER throw away an original part from your Corvette. Someday, you'll want to use it to evaluate how to modify your reproduction part to fit correctly, or you'll want to rescue it and refurbish it to replace the reproduction part you purchased that would never fit no matter what you did.

You think I'm kidding. Just wait.

Patrick

[Joseph A.]

Re: 78 Vette Coil Springs & Liners

Patrick: Thanks for the Info. The liners that I removed from the spring were metal not black plastic. I just looked at my judging guide and it states that FE7 cars had black plastic H-shaped liners between the leafs of the spring. But it does not go into good detail on what type of liners were on base suspension cars like mine.

Joseph Adelizzi

[Patrick H.]

Re: 78 Vette Coil Springs & Liners

Same black H-shaped plastic liners for all the springs.

I do wonder if your spring is a replacement if, in fact, it had steel liners.

Patrick

[Patrick H.]

addendum

The only difference I can think of is that the spring width changed in (I believe) 1978. To the best of my (post-72) knowledge, the appearance of the springs and liners did not change. Now watch - a 78 fan will jump in and say they came with steel liners. I don't recall ever seeing one that way, though.

Patrick

[Tom R.]

Re: 78 Vette Coil Springs & Liners

Joseph:

Patrick is steering you correctly...zinc liners were introduced later but in 78 we use the black plastic. 1978 probably had more front spring configurations than any other year due to the 60 and 70 series tires for both base and FE7. Again, as Patrick indicates...stick with what you got.

But it sounds like your rear spring is a later model leaf spring (post 1980)and no telling what its rating is and could even be an FE7. You could use the AIM and check trim height and determine if it complys with specs as recommended by the factory. Or...simply determine if it works for you and stick with it.

[Joe L.]

Re: 78 Vette Coil Springs & Liners

Joseph-----

The spring liners on your car were, indeed, made of metal and the metal was a high zinc alloy of some kind. It's a relatively soft material. The standard spring for 1978 was a 2-1/2" wide piece and all 2-1/2" wide springs used this zinc alloy liner. These liners were of GM #462589 and are long-since discontinued. I know of no reproduction, although this material may be used for other springs and may be available in the spring manufacturing/service industry. The FE-7 spring was 2-1/4" wide and used the black, graphite-impregnated polypropylene, "H" cross section liners which are, indeed, still available from GM.

All of the front coil springs on the market today are pretty much "generic". Your original springs were specific to the vehicle weight range of your car. The weight range depends upon the vehicle's originally installed options and I can't tell you which is the correct spring without that information. In any event, ALL of these springs, GM #346939, GM #346940, and GM #346941, are GM-discontinued as are ALL 1953-82 Corvette springs. Eaton Detroit Spring will be the GM-licensed reproduction source for this spring but whether they actually manufacture it, true to original GM specs, is questionable, at best.

As Patrick mentions, I would clean up and re-use your original springs. If they suffer from no significant corrosion damage, the chances are that they are fine for re-use.

[Patrick H.]

Re: 78 Vette Coil Springs & Liners

See what I get for trying to go later than 72. I knew you'd have the answer for him. At least I knew the spring width change might also involve the liner change.

He may be able to find some liners from a spring shop which are reasonably close. I'd be surprised if the originals were still reusable. I have yet to see a plastic liner I'd reuse.

Good luck, Joseph.

[Joseph A.]

Re: 78 Vette Coil Springs & Liners

Thanks guys for all the info. I really enjoyed reading all the knowledge you guys have.

Thanks Again

Joseph Adelizzi