69 bb convertible rear spring installed and car is "jacked up"

[Brad H.]

Guys,
I have just completed a body off chassis restoration and reinstalled the body with new solid body mounts and the same number of shims as it came off. I installed a rebuilt rear 9 leaf spring (removed from a 69 Corvette, blasted the steel and repainted the parts. New rubber separators were also installed. When I bought the car it had a composite spring on it, so I removed it and used a factory rear spring. Problem is the rear end appears jacked up and the clearance from the top of the tires to the wheel well lip is way up. I see no installation errors. Is this a condition that after some use will tend to settle out? I've read about this issue, but I don't see this coming down that much. Everything is new or rebuilt thruout the entire chassis. I was hoping someone might have some experience with this. On my other 69, the spring was removed and rebuilt the same way but it did not jack up the rear end. HELP????
Thanks,
Brad

[Stephen L.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

2 Questions: Is the car completely back together? complete interior bumpers etc. Have you at least rolled the car around if not driven it?

[Michael G.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Guys,
I have just completed a body off chassis restoration and reinstalled the body with new solid body mounts and the same number of shims as it came off. I installed a rebuilt rear 9 leaf spring (removed from a 69 Corvette, blasted the steel and repainted the parts. New rubber separators were also installed. When I bought the car it had a composite spring on it, so I removed it and used a factory rear spring. Problem is the rear end appears jacked up and the clearance from the top of the tires to the wheel well lip is way up. I see no installation errors. Is this a condition that after some use will tend to settle out? I've read about this issue, but I don't see this coming down that much. Everything is new or rebuilt thruout the entire chassis. I was hoping someone might have some experience with this. On my other 69, the spring was removed and rebuilt the same way but it did not jack up the rear end. HELP????
Thanks,
Brad

Brad,

I've restored many original springs back to original specs and to date have never had a spring react as you've described. As Stephen has stated all components of the car will need to be in place on the car, car rolled around and or driven to know if something is not quite right. Installation of these springs is fairly straight forward barring as you stated "installation errors. Are the end bolts which hold down the spring in place in conjunction with trailing arms the correct length? Shorter bolts will place additional stress on the spring causing the car to be "jacked up".

[Bob H.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

As Michael said check those bolts. I'm not as familiar with a 69 but shouldn't the big block have a 7 leaf spring?

[Dale C.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Bob, it depends, the F41 was the seven leaf option and not on all 427 vettes. Dale

[Michael G.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Bob, it depends, the F41 was the seven leaf option and not on all 427 vettes. Dale

9-leaf spring was standard, 7 leaf spring optional HD on small and big block vehicles.

[Michael W.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Although you removed the spring from a '69 Corvette, it may have been an aftermarket replacement and not an original. Many replacement springs give cars a sky high rear end and are compensated with by using longer end bolts.

[Brad H.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Thanks guys. It is a factory spring and most of the 427/390 cars did have the 9 leaf spring. The 7 leaf is stiffer but that's not what I have. Michael, I don't suspect a problem with the spring. It looks great and there really isn't much to it as far as build up issues. The spring bolts were purchased from Volunteer Vette and supposedly are the correct length but I don't have the originals to compare them to. The car has nearly all of its components back on it and it has been rolled around some. I have added some more weight to the back and it seems to be resistant to it as far as lowering any. If someone has the correct length of the spring bolts, I can check that. The chassis work was done professionally by Classic Restorations. This is my second 69 so I am very familiar with it, but I just don't see any obvious problems. It really acts like the spring is too strong but I don't see how that could be since it was not rearched and is a removed from Corvette spring. I'm hoping that maybe it will tend to squash some after use but I think that's wishful thinking. The restoration shop guys don't have an answer either. Thanks for any ideas this might generate....
Brad

[Michael G.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Thanks guys. It is a factory spring and most of the 427/390 cars did have the 9 leaf spring. The 7 leaf is stiffer but that's not what I have. Michael, I don't suspect a problem with the spring. It looks great and there really isn't much to it as far as build up issues. The spring bolts were purchased from Volunteer Vette and supposedly are the correct length but I don't have the originals to compare them to. The car has nearly all of its components back on it and it has been rolled around some. I have added some more weight to the back and it seems to be resistant to it as far as lowering any. If someone has the correct length of the spring bolts, I can check that. The chassis work was done professionally by Classic Restorations. This is my second 69 so I am very familiar with it, but I just don't see any obvious problems. It really acts like the spring is too strong but I don't see how that could be since it was not rearched and is a removed from Corvette spring. I'm hoping that maybe it will tend to squash some after use but I think that's wishful thinking. The restoration shop guys don't have an answer either. Thanks for any ideas this might generate....
Brad

Quick measurement of my spring bolts comes in around 6 1/2"-6 5/8". Any shorter than that will again bring more tension on the spring lifting the car higher. If the bolts are in the vincinity of this measurement don't let it be of concern right now. As car gains weight through the addition of components and including driving around believe you'll see a change in the disposition of your suspension. I've personally wittnessed this through mulitiple restorations.

[Brad H.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Thanks Mike,
I'll check that. I'm hoping as you say that it will settle some and the additional weight will help as well. I'll get back with you when I get that done. My SB 69 spring is much less arched than this on sitting flat on the ground. It will be interesting to see how it does.
Brad

[Michael G.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

My SB 69 spring is much less arched than this on sitting flat on the ground. It will be interesting to see how it does.
Brad

Keep in mind the rear spring for the SB and BB engines were the same.

[Bill C.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

just a fyi --

my 72 sat high until I drove it around for about 10 miles then it dropped significantly.

also - the car sat funny until I had the camber correctly set on the trailing arms.

bill

[Brad H.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Thanks Bill, I was hoping that might be the case. If it doesn't come down after some driving, I'll post again. In the mean time - fingers crossed......
Brad

[Kenneth B.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

A full tank of gas,a spare tire under it will add weight & driving it might make it settle.

[John B.]

Re: 69 bb convertible rear spring installed and car is "jacked up"

Brad, I'm concerned with exactly the same problem on the 68 BB convertible that I am restoring. I did the same as you, rebuilt an original 9 leaf spring and replaced all the bushings, etc. My car is still a shell on the frame, but the rear is very high and very stiff. I realize that without a drivetrain and all the other stuff that remains to be installed, it is premature to be too worried that there is some problem, but having two 200 pound buddies sitting on the car over the rear wheels does very little to change the height of the rear. I have been through the suspension several times, including one time where I removed everything, disassembled the spring again and put everything back together being very careful to make sure there were no mechanic induced errors. Got the same result, very high and very stiff. So, at this point I too am hoping that when I get it all together and drive it a little, it will settle down. John