Correct rear spring for a '65 convertible

[Joseph E.]

I've posted several questions today about rear springs and an answer by Harry Sadlock prompted me to look at the spring of my '65 convertible that is currently under restoration. Harry says that the rear spring for a 1963 corvette has leaves that all follow the arch. The spring out of my low mile (36K) 1965 is a nine leaf rear spring where all of the leaves follow the arch. There is an additional piece of flat steel on top of the ninth leaf (counting from the bottom up) that is smaller than the ninth leaf. Is this spring correct for a 1965 L76 powered small block car and what is the steel plate on top of the last leaf for? Thanks again for any responses and information.

Joe

[John H.]

Re: Correct rear spring for a '65 convertible

The spring out of my low mile (36K) 1965 is a nine leaf rear spring where all of the leaves follow the arch. There is an additional piece of flat steel on top of the ninth leaf (counting from the bottom up) that is smaller than the ninth leaf. Is this spring correct for a 1965 L76 powered small block car and what is the steel plate on top of the last leaf for? Thanks again for any responses and information.

Joe

Joe -

Your spring is some sort of aftermarket replacement. The original 9-leaf spring had the bottom six leaves cambered, and the top three were flat. The spring Harry described is the correct one-year-only 1963 design; 1964-up (except F-40/41) all used the same 6/3-leaf spring. The 7-leaf F40 spring was only available in 1965 on the 327/375 fuelie and on the 396/425 L-78.

[Joseph E.]

Re: Correct rear spring for a '65 convertible

John,

My description of the spring in my '65 was slightly incorrect. The first eight leaves are arched, the last and smallest (9th) leaf is straight. The ends of the 2nd through 9th leaves have the upward curve one would expect to see and its appearance is original. The first spring (the longest) has the correct 45 degree cuts on the four corners. The center bolt appears to be original as it has a slight recess with the letter "M" in it and it is also the correct length. I've seen original center bolts in the archives and this one matches up with them. I'm still wondering what the eight inch piece of flat steel is that sits on top of the ninth leaf. This piece of steel also has all four corners "clipped" but they don't look like the angle is 45 degrees, it appears to be less. I still don't understand what this piece of steel is for and what it is doing in place on this spring. The undercarriage of this car and its components all have the same age (rust and dirt buildup) to it so I always assumed that the suspension components had never been fooled with. This spring doesn't look like any of the aftermarket ones that I've seen photos of on the site. If the seventh and eighth leaves were flat like the ninth one is, I'd swear that this was a GM spring but the other characteristics of the spring still seem to indicate that it is GM. Does anyone have any more input on this spring? I'd post some photos but I'm not sure of how to do this even though I have a digital camera. If anyone can help with instructions for posting photos, I'd be glad to try if there is an interest in seeing pictures. Thanks.

Joe #45420

[Jack H.]

Re: Correct rear spring for a '65 convertible

Per your description, expect a judging deduction for the spring currently on your '65 as it's Not Typical of factory Production (NTP). Yes, the '63 was an exception to the mid-year cars in that it had 'single stage' construction/geometry (all leafs arched alike).

Starting in '64, the design changed to a 2-stage configuration where the bottom leafs were arched and the top leaves weren't. That gave the spring one set of compression (spring rate) characteristics under mild/normal use and a second (stiffer) compression profile under AGGRESSIVE compression when the 1st stage flattened out to the point that it met the second stage leafs...

[Wayne M.]

Re: Correct rear spring for a '65 convertible

These pics of the top 4 leaves of a '65 9-leaf spring might help.