1980 Gymkhana Rear Spring

[Mark K.]

I recently bought a 1980. The rear spring was replaced with a TRW fiberglass by the P.O The original spring came along
with the purchase. The car appears to have gymkhana suspension. The front sway bar is 1-1/8". The rear sway bar is 7/16".
The spring is 2-1/2" wide and 9 leaves. The liners are zinc. The spring is painted grey in a sloppy fashion. The only markings
I could find are the letters NML with the numbers 01133 under the letters, stenciled in blue paint. The corners of the main
leaf are cut at a 45 degree angle. Is this a gymkhana spring?

Mark Kopcza

[Gary B.]

[David H.]

Re: 1980 Gymkhana Rear Spring

I recently bought a 1980. ... The car appears to have gymkhana suspension. ...

Mark

If you don't already have your tank sticker (build sheet), a "Shipper" document with RPO codes, delivery date, dealer, VIN, etc is available from GM Archives. Last I looked, document was $50 - years ago it was gratis, but that was years ago ...

Dave

http://www.gmmediaarchive.com/?page=1

p.s. 1977 and forward Chevrolet

[Tom R.]

Re: 1980 Gymkhana Rear Spring

I recently bought a 1980. The rear spring was replaced with a TRW fiberglass by the P.O The original spring came along
with the purchase. The car appears to have gymkhana suspension. The front sway bar is 1-1/8". The rear sway bar is 7/16".
The spring is 2-1/2" wide and 9 leaves. The liners are zinc. The spring is painted grey in a sloppy fashion. The only markings
I could find are the letters NML with the numbers 01133 under the letters, stenciled in blue paint. The corners of the main
leaf are cut at a 45 degree angle. Is this a gymkhana spring?Mark Kopcza

Yes! The NML is the broadcast code for a 1980 FE7 rear spring. The pastel blue paint on the spring is typical of the coding on the spring. Rear shocks had (have) labels that are ZA and ZE. Front spring labels would have been similar to BHJ. I have a couple of 1980 build sheets and confirm your numbers/codes.

[Mark K.]

Re: 1980 Gymkhana Rear Spring

The main leaf measures .235 thick. Since the previous owner was not the original owner I am concerned that the spring may have been changed.
The judging manual states that part# 14021604 is stenciled on the main leaf. This number is not present. The spring does not have any retainer bands.
I believe that the car is a FE7, but I'm not sure about the rear spring.

Mark Kopcza

[Gary B.]

Re: 1980 Gymkhana Rear Spring

The .006” difference in main leaf thickness From the 0.229” I quoted could just be from paint or slightly tilted digital calipers when measuring. Can you post a close-up photo of the end of one of the spring leaves, but not the main?

Gary

[Gary B.]

Re: 1980 Gymkhana Rear Spring

?..Since the previous owner was not the original owner I am concerned that the spring may have been changed...

[Mark K.]

Re: 1980 Gymkhana Rear Spring

Did the standard and FE7 springs both use zinc liners?

Mark

[Gary B.]

Re: 1980 Gymkhana Rear Spring

Mark,

I don’t know. My knowledge of the standard spring only goes thru the 1977 model year. Joe Lucia probably knows the answer.

If I had to guess one thing about the standard 1980 spring it would be that the leaves are not 0.229” thick. Do you know if each of the leaves in your spring are the same thickness? Yes, I know it’s hard to measure them without dismantling the spring. But can you try to measure with the spring assembled? In the article that Joe and I wrote on HD springs we speculated that all leaves were the same thickness in the 1980 HD spring.

Gary

[Mark K.]

Re: 1980 Gymkhana Rear Spring

Gary,

Visually, all of the leaves appear to be the same thickness. I will take the spring apart to confirm.

Mark

[Gary B.]

Re: 1980 Gymkhana Rear Spring

Mark,

You don’t need to dismantle the spring, unless you really want to, say for repainting. I only asked because Joe and I didn’t have access to any technical info or drawings for the 80-82 HD spring, do we had to estimate. Also, if you could measure the total assembled thickness, right next to the center bolt, that would be useful info for me. Joe and I estimated the total assembled thickness of the 80-82 HD spring to be 2.301”.

Gary

[David H.]

Re: 1980 Gymkhana Rear Spring

... Also, if you could measure the total assembled thickness, right next to the center bolt, that would be useful info for me. Joe and I estimated the total assembled thickness of the 80-82 HD spring to be 2.301”. ...

Gary

My 1980 with FE7 is just over 2.5 inches. Difficult to be exact given wear, rust, age, dirt, and damage.

Dave

IMG_1575.jpg

[Gary B.]

[David H.]

Re: 1980 Gymkhana Rear Spring

[Mark Kopcza: ... The main leaf measures .235 thick. ...]

The .006” difference in main leaf thickness From the 0.229” I quoted could just be ...

Mark/Gary

Main leaf on my 1980 measures 0.237 very similar to 0.235 Mark measured on his main spring.

Dave

[Gary B.]