C3 rear spring

[cool80]

I am in the process of replacing/repairing/detailing the rear end of my 1980 Corvette. One of the issues is the condition of the spring. The spring is not flat and appears to have some life left, however the insulator pads that stop each leaf from rubbing together are shot. Also the spring is a 10 leaf spring. In addition, I overhauled the front suspension and when I replaced the sway bar bushings they were 1 1/8" which indicated a HD suspension. I am worried about the height of the rear end since I did not replace the front springs. Any suggestions.

cool80

 

[celeryman22]

I just got done replacing my rear spring. I bought a fibreglass spring from v,b and p, they are on sale now. My front sway bar also used 1 1/8" bushings. Can't remember how many leafs in the spring. I believe rear height can be adjusted by the two bolts on the end of the spring. I was very happy with the kit from them, just have to wait and see how it rides now.

 

[Vettehead Mikey]

You can buy new spring liners if you want. If your ride height is OK, I would keep the existing spring.

 

[cool80]

Thanks Mikey, great idea. Since I am satisified with the height and if the spring is not cracked I would perfer to use it. Where can you purchase them??

Thanks cool80

 

[patsnitrovette]

Vette brake products sell the longer end bolts, i went with a 360# rear composite spring and 8 inch bolts,still didnt like it then i ordered the 10 inch bolts from them and got the height where i liked and trimmed them off.They probably sell the liners too or mid america,ecklers or others.

 

[Ludigdrums]

Is there any difference between using lowering bolts verses a different weighted spring? Mine sits okay with 8" bolts, but with 10" (where it was perfect) it caused the half shafts to go horizontal. Would a different spring give different results as far as the half shafts?

Thanks!

- Jeremy

 

[Stallion]

Is there any difference between using lowering bolts verses a different weighted spring? Mine sits okay with 8" bolts, but with 10" (where it was perfect) it caused the half shafts to go horizontal. Would a different spring give different results as far as the half shafts?

Thanks!

- Jeremy

Well wouldn't this be based on the height and placement of the drivetrain? I don't see how a different spring would help that out in a similar ride height, correcting the half shaft angle problem. No?

 

[Jacko]

I want to raise the rear end of my '79.
How do I do it with the rear spring?
Thanks

 

[Ludigdrums]

Stallion: That's what I think...there shouldn't be a difference which way you do it, it will still affect the frame/half shafts the same way.

Tony: Thanks for your reply. I actually have your 550lb springs in the front, which put it right where I want it. But, like I said earlier, in the back when I put the 10" bolts in, it made the half shafts sit too horizontal (which I'm told is no good). Unfortunatelly, I liked where the fender sat with the 10", but don't want to mess up my half shaft/U-Joints. Can one of your springs correct the gap without affecting the half shafts? I can't see how. Please enlighten me! Thanks!

- Jeremy

 

[Stallion]

Our spring would eliminate the need for 10" spring bolts but, the relationship of the half shafts to ride height would not change ( horizontal is good ) providing the spring rate is sufficant to prevent the rear end from dropping durring launch when drag racing. What spring spring are you currently running ?


Tony
VBP

Is horizontal good? I thought our IRS was designed and is best at a certain angle. I mean, it would make sense that horizontal would be fine, such as a solid rear axle, but is this true? Would you be eating up u-joints with 180 degrees from half shaft to diff to half shaft?

 

[JohnZ]

Is horizontal good? I thought our IRS was designed and is best at a certain angle. I mean, it would make sense that horizontal would be fine, such as a solid rear axle, but is this true? Would you be eating up u-joints with 180 degrees from half shaft to diff to half shaft?

The Corvette IRS system is designed with a permanent running angle for the half-shaft U-joints, but it's in the plan view (top view), with the spindle centers slightly forward of the diff yoke centers, so it doesn't matter what angle the half-shafts are in vertically - they'll always run at an angle regardless of rear suspension height. All front-wheel-drive cars are done the same way for the same reason .

 

[Ludigdrums]

Hmph...this is interesting!

Tony...I have a stock replacement 9 leaf from Corvettes Unlimited here on Long Island, NY. The previous owner had it done there...and they said, it is what they always use. I had it out of the car and the arc was pretty extreme.

I'm glad to here that horizontal is good. Check out this older post http://www.corvetteactioncenter.com/forums/showthread.php?t=58634.

My previous U-Joints got eaten up after only 2000 miles. They were the ones with the grease fittings on them. In fear that this would happen again...I got Lakewood heavy duty u-joints, and went from the 10" to the 8" spring bolts.

So, I guess the consensus is that it is okay for the half shafts to be horizontal?! I would love to bring the rear back down with the 10" bolts, but don't want another alignment!

- Jeremy

 

[cool80]

Tony, have you ever seen a 10 leaf spring on a C3.

cool80

 

[cool80]

Tony, my corvette has a 1 1/8" front sway bar. Does that indicate a heavy duty suspension? In addition, I do not have a rear sway bay??? Is that unusal?


cool80

 

[Ludigdrums]

Tony,
Thanks for the advice. I don't have the 10" bolt on there now, but when I did, there didn't seem to be much of clearance issues...but I know what you mean if I got a flat tire or something.

What would you recommend as far as spring sizes for me? I have your 550lb front springs, 18x10 wheels (4" backspacing) with 255/40/18 front and 285/40/18 back w/offset trailing arms, and your smart struts (which are awesome!) It's an '81 also by the way.

Also, I have no rear sway bar....but I've heard mixed opinions on whether or not it's need when you have wider tires like myself...any thoughts?

Thanks!

- Jeremy

 

[celeryman22]

Tony, my corvette has a 1 1/8" front sway bar. Does that indicate a heavy duty suspension? In addition, I do not have a rear sway bay??? Is that unusal?


cool80

I also have the 1 1/8" front sway bar and not rear bar. Same year 1980.
For what its worth.

 

[vmrod]

Jacko,

I think you were told that in order to raise the ride height of your rear end, that you need longer bolts. I don't think that is the case. All you need to do, is to tighten up the nut you have on your existing setup.

The shorter the bolt (or distance) the higher the ride height. The longer the bolt = a lower ride height.

 

[Jacko]

VMROD.............thanks, that was exactly the info I was looking for!
Jacko