70 Ride Height
After 2 years the body is back on the frame. My problem is now the ride height is not correct. The front is at 30.5 in. and S/B approx. 28 in. The rear is at 31.5 in. and S/B approx. 28 in. I purchased the leaf sring and front coils from Corvette USA (ads run in the Driveline). I was told the leaf was a rebuilt original and the coil springs original, but used GM 11 coil. The leaf does not sit flat, having a large arch. The car has been rolled back and forth several times and the camber adjusted. Also the car is non air. I spoke with Gary Beaupre this evening and he suggested I post for any thoughts and if anyone has any experence with Corvette USA springs. I would greatly appreciate any and all feedback as I am registered for the Jenkintown meet on Oct. 11 and this issue could be a significant barrier to my getting the car judged. Tx.
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Terry -
Re: 70 Ride Height
Terry
The numbers quoted came directly from the AIM. We measured, as detailed in the AIM, using the apex of the wheel wells as the reference point. That being said, if I am not using the numbers correctly please advise me of the proper procedure. The car looks like a mud buggy and I would appreciate any info. on possible causes/solutions and if anyone has used Corvette USA springs.Comment
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TerryComment
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Re: 70 Ride Height
Joseph----
With the suspension normalized (i.e. the car rolled back and forth with the weight on the suspension), there should be little or no arch observed in the rear spring. There might be just a slight amount of positive arch, but VERY little. This would be true even if you have improperly tightened various suspension bolts prior to normalizing the suspension. That will cause excessive strain on the various associated rubber bushings but it will not affect the ride height.
So, if you have a pronounced arch at the rear spring under the condition of a normalized suspension, I would say there's a problem with this spring.In Appreciation of John HinckleyComment
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Re: 70 Ride Height
Joseph,
You mentioned a rebuild original for the rear spring. Does it have the flared ends to the leaves? Have you compared the widths and thickness of the leaves to an original? I too purchased a replacement rear spring (C. Central) and had the dune buggy effect. The unforseen key to my problem was the term "exceeds OEM specifications" used in the description of the spring. Oh boy, did it exceed the specs.Comment
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Re: 70 Ride Height
I believe the problem has to do with the spring itself, based on the fact that that there is significant arch despite the body being back on the frame. All fastners are loose so nothing should be hanging anything up. The ride height was measured using, I believe, the R and P dimensions described in the AIM.
I am going to call Mike at Corvette USA and try and get some answers from him as he sold me the spring.
As previously mentioned my front ride height is too high by about 2.5 ins. I'm not sure of the part number on the springs, but they were ordered based on the specifics of the car ie no air/454. They have what appears to be 11 coils. Any comments or thoughts?Comment
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'70 Ride Height
Joe,
I agree with Michael's suggestion. Measures the thickness of each leaf and compare with the GM specs that are probably in one of my articles on leaf springs. You say the rear spring was a rebuilt original, so it should be to GM spec. If the width and leaf thicknesses are correct and if it has the correct free arch, then I think the rear ride height should settle into the correct range after a shake-down drive with gas in the tank.
If the spring is a restored original, what did the vendor do to restore it? Was each leaf re-arched & re-heat treated? Or was it a simply strip, repaint, & new liners.
GaryComment
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Re: '70 Ride Height
Gary-----
This is the key. As a matter of fact, though, if all that was done was to strip, repaint, and install new liners, I doubt there would be any problem, at all, and certainly not a problem with too great an arch when installed. If the rebuild included "fancier" sort of things, that's likely what caused the problems with it.In Appreciation of John HinckleyComment
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Re: 70 Ride Height
Tx all for the continued responses. I talked with Corvette USA today and he reaffirmed the spring is GM rebuilt unit. I don't know/didn't ask if any
"fancy" processes were used in the rebuild. He did say the leafs S/B marked with GLS or GMU. He wants me to take pics of the current set up, send to him for viewing, and we'll talk later this PM. I'll post later if I learn anything new.
I haven't had any comments on the front coils and the high ride height. Please comment with any thoughts.
Tx again.Comment
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Re: 70 Ride Height
Hi Joseph,
Is the car completely back together?
It will sit high until EVERTHING is there. The 'curb' load dimensions even include a full tank of gas.
When I put the bare body back on my 71's completed chassis the term "dune buggy' certainly came to mind.
Jut a thought!
Regards,
Alan71 Coupe, 350/270, 4 speed
Mason Dixon Chapter
Chapter Top Flight October 2011Comment
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Re: 70 Ride Height
Alan
Everything is in except the interior, gas and spare tire. Was yours off several inches like mine in the front and rear? TxComment
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Re: 70 Ride Height
I have yet to see / hear of a set of replacement springs - front or rear - that give exactly the same ride height as original springs no matter what a vendor states. If your original front or rear springs are at all salvageable or restorable, my suggestion would be to think about reinstalling them.
And, as Terry said, you have to be sure the front A-arms were torqued with the whole body and frame on the ground.
PatrickVice-Chairman (West), Michigan Chapter NCRS
71 "deer modified" coupe
72 5-Star Bowtie / Duntov coupe. https://www.flickr.com/photos/124695...57649252735124
2008 coupe
Available stickers: Engine suffix code, exhaust tips & mufflers, shocks, AIR diverter valve broadcast code.Comment
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Re: 70 Ride Height
On the subject of rear leaf springs, I am considering replacing the liners on my factory springs , has anyone noticed an increase in height afterwards without re-arching springs ? It seems like this would increase heigth but how much and is it worth the effort. I never liked the rear height on any c-3's I have owned and I usually installed a spacer below spring that helped a lot. SteveComment
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Re: 70 Ride Height
Patrick-----
I agree, one needs to be sure that the suspension bushing retainer bolts are torqued with the suspension normalized. However, if the bolts are torqued with the suspension not normalized, I don't think it will result in any significant affect on ride height when the suspension subsequently becomes normalized. What occurs is that if the bolts are torqued with the weight off the suspension, the bushings are then "loaded" when the suspension is in the normalized configuration. That's the opposite of the way it's supposed to be.
Why do I think this? Well, many years ago I made this mistake myself (out of ignorance, I'm ashamed to say). I noted no visible difference in ride height as a result of the mistake. I'm not saying there was absolutely no difference in before-and-after ride height but, if there was, it was not enough that I visually perceived it. Sometime later I became aware of my mistake and immediately corrected it. I raised the car, released the torque on the bolts, lowered the car, normalized the suspension, and re-torqued the bolts. I perceived no difference in ride height then, either.In Appreciation of John HinckleyComment
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