65 GS coil spring specs

[Mark Ascher]

Hi Rob,

I'll let you know tomorrow or Wednesday. I'm picking up the rear springs from the powder coater.
He has the box with the packing slip. Did you check the front stabilizer bar bushings, mounts & links?

Mark

[Robk]

So I finally got around to trying to install these new springs from espo.   The rears were a full coil to short.  I then took the car to a buddy's garage to have him install the fronts and they were about two inches shorter than the orginals.  So the old ones went back in.  Either espo is not  consistent with their products or these part numbers arent correct.    The fronts that were too short were C-CS-656.  Anybody have better luck with different products?

Rob K

[WkillGS]

Rob, were the new springs a larger diameter wire? They will be shorter out of the car, but may compress to a similar height when installed.
The rears go in & out easy enough....did you try installing them?
The '66 GS front springs go in & out fairly easy. I barely had to compress them to install them. The stiffer (and possibly shorter) 65 GS springs should be a bit easier to install.

Buick did spec a lower ride height for the GS than the Skylarks.

[Mark Ascher]

Rob,

The ESPO springs I ordered worked perfectly. I'd have to scrounge the part numbers, but ride height, etc. looks great so far.
I'm curious if you put them in and got the car on the ground. Just measuring the free spring height won't tell you everything.

Mark

[Robk]

I pulled  the rears myself with a friend but the fronts were a bit intimidating so I brought them to the garage of another guy i know.   At first I figured only the rears were the wrong size since the new fronts had 11 coils like the old ones (I counted the fronts)   The old ones (rear) were  much taller than than the new ones  ( a full coil of spring) so I put the old one back in. 

I am a bit confused by Walt's message.  The gauge of wire looked about the same to me.  Are you saying that the new ones would compact less than the old ones and therefore perfrom the same as the old ones?   IF that is the case maybe I do have the right ones.

mark - were your old ones and new ones the same height out of the car?


as always, thanks  Rob

[Mark Ascher]

Rob,

Before shipping anything back, I'd go through the exercise of getting them in the car. The wire diameter might be close,
but the steel spec can be different, ie; stiffer, looser, etc.

The old ones from my car hit the trash bin in 1996. I should have saved them, but someone had already changed the rears
to a cargo-type overload spring, so I didn't have original rears. The fronts were pretty worn out, but I should have saved one.

I bought front & back springs from the GSCA in 1996, and they were in the car until last year. I don't know what they sent me,
but the car sat about 5 inches higher than stock, even with the engine in. Right now, with the ESPO springs in, it looks good -
a little higher in the back actually than what I would like, but I still need to get to get some glass, interior, etc. in the car.

Pat Guida put ESPO springs in his 4 speed convert as well, and was very happy with them.

Mark

[Robk]

That's encouraging.   My only worry is that they somehow sent me the wrong ones.  The rears were not that tough, but putting the fronts in, having them, be wrong, and taking them back out and putting my old ones back in is a rough way to spend an afternoon.

Rob

[WkillGS]

Rob, here's an example of thin wire vs thick wire and free length:

A Moog #5246 spring for a plain Skylark.... Wire dia is 0.630" and the free length 17.3 ". Rate is 314 lbs/inch. (thin and tall)

For a '66 GS (different than '65 GS), a Moog #6033 spring is a perfect match for the originals. Wire diameter is a thicker 0.660" and the free length is 16.4 ". Rate is 369 lbs/inch. (thick and short)

Now, and this is overly simplifying it (and not entirely accurate), add 1978 lbs to the #5246 spring and it compresses from 17.3 " to 11" (which is the installed height when in the car).
Apply the same 1978 lbs to the thicker, shorter, #6033 spring, and it also compresses to about 11".
.....the taller weaker spring compresses 6.3 inches, while the shorter thicker spring only compresses 5.4"......

The correct spring for a '65 GS is supposedly stiffer than the 66 version, so it's likely to be a bit shorter and a thicker wire.
Is your springs height in this range?

[Robk]

I'll measure it tonight.  Thanks Walt.

With the rears the difference was so dramatic it did not occur to me that it could relate to the rate.

I'll keep working on it.

Rob