C2 leaf spring rates

[Tim Sargent]

I have a 67 427 air conditioned car with std suspension (not F-41) can anyone tell me the correct spring rate for the 9 leaf rear spring. I want to have mine re-arched.
Thanks
Tim

[Duke W.]

Re: C2 leaf spring rates

The fixed rate 1963 rear spring has a rate of 162 pounds per inch. The later C2 spring rate was variable and IIRC the rate at ride height is 140 pounds/inch. This data is in the AMA specs that GM will send to any vintage Corvette owner.

I suggest you rethink "rearching" the spring? Why do you think this is necessary?

Unless the leaves are signficantly corroded, it probably still has its original characteristics.

The most common cause of lost rear ride height is compressed spring link cushions. They should be replaced about every five years, whether the car is driven or not.

If the spring is not signficantly corroded, a simple rebuild with new liners and link cushions will usually make it look and feel like new.

Duke

[Joe R.]

Re: C2 leaf spring rates

Tim:

Duke is right that old rubber donut bushings can make the rear sit lower than it should. Consider replacing these first to see how much it improves things. It's a simple 1-hour job.

The rear spring is supposed to be flat or curved slightly downward when the weight of the car is on it. If the ends are pushed up higher than the middle, then you probably do have a tired spring.

Before you do any spring work, I suggest that you review Dennis Dalton's article on spring restoration in the Spring 2005 Restorer. Also review Gary Beaupre's series of articles that are referenced in Dennis' article. Gary provides a lot of information on how the Eaton replacement spring differs from the original.

Some people don't like re-arching, but I think it is okay if it is done properly (with heat treating and shot peening). The Eaton web site has some useful technical info on re-arching at:

http://www.eatonsprings.com/rearching.htm