65 rear spring problem
I put my original 31,000 mile rear spring & rear control arms on last week . I never noticed it when I took it off or painted it , but I have a gap on the right rear side of the rear spring . the front side looks good . I dont know if it is getting ready to break or is just weird looking . I have two used main leaves one is on a 10 spring and it looks about the same . The other I dont remember where it came from but it looks ok on the floor . What do you think leave it alone or put my used one on ? I dont want to use a repro if I can help it .DSC_1764.jpgDSC_1765.jpgDSC_1763.jpg
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Re: 65 rear spring problem
That main leaf is fatigued and on it's way out. If you set the weight of the car on it I would bet that side will ride lower than the other now and will break at the inboard end of that gap in time.
It may have only 31,000 miles, but it's still 50 years old and most likely had the weight of the car on it for most of those years. As much as we are reluctant to use repro parts, some things are just not meant to be in service that long.
That's the third one like that, or broken, that I've seen in as many weeks.
Steve -
Re: 65 rear spring problem
Yea Steve I know your right ,its just a pain to change with the body off . Does anyone sell just the main leaf ?Comment
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Re: 65 rear spring problem
Bill , I have a friend who had the same problem and what he did was get a Eaton spring and used the main leaf, this is really the only spring that is like the factories, the others are not really the same. Its not the cheapest way to go but worked great. and keeps the originality in tack.New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.Comment
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Re: 65 rear spring problem
I needed new main leafs for the springs on my Mopar. Went to a local spring/alignment Co and was able to order just the main leafs. They had a listing for the many variations of all cars, police, taxi, etc. and selected a "station wagon" leaf as I wanted to stiffen up the original springs.Comment
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Re: 65 rear spring problem
Bill,
I did what Ed suggests, which is to buy an entire spring from Eaton Detroit Spring and I just used their main leaf; the other leaves of the Eaton spring do not have the correct taper-rolled ends. The Eaton main leaf is somewhat thicker than the original GM main leaf. I think I show in one of my Restorer articles on rear leaf springs what that net effect of using the Eaton main leaf is. It's a tiny bit stiffer based on an actual stiffness test, but not enough to write home about. And the thickness difference is also not easy to detect without using a caliper.
GaryComment
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Re: 65 rear spring problem
Bill,
See a private message.
DougComment
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Re: 65 rear spring problem
All,
Here are some of the test data that I reported in an article for the Restorer back in 2000 or 2001. In addition to the AMA engineering specs for the Corvette 9-leaf spring, I used an industrial capacity servo-hydraulic testing system to test three 9-leaf springs: an unrestored, original GM mid-year spring; a new report spring (from Eaton Detroit); and a spring created by using the main leaf from the Eaton spring along with leaves 2 thru 9 from the used GM spring. As you can see in the table, the repro spring was the stiffest, 200 lb/in vs the 140 GM design spec vs 130 for the used spring. By removing the GM main leaf and swapping in the Eaton main leaf, the resulting stiffness was 139 lb/in, basically spot on the AMA spec. I estimated that by using the Eaton main leaf the ride height would increase by 0.22", but that estimate was based on my testing setup which is undoubtedly different from the real setup that AMA/GM used to determine the stiffness and displacement. My gut feeling is the 0.22" change would be an upper limit on what one would find. After all, 8 of the 9 leaves are original GM leaves, so the effect of using the Eaton main leaf is not likely to be that substantial given that it is not too much thicker than the original GM main leaf.
Gary
Spring test data.jpgComment
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Re: 65 rear spring problem
Bill I would wait until you have everything on the rear suspension with the body and wheels then I would decide if there is a problem or not. I had the same kind of issue but once everything is loaded it turned out fine.
MikeComment
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