Rear Suspension

[Bradley D.]

Is this correct?
At the end of the leaf spring on the left side, the lenght onf the bolt is at the end, while on the right side the bolt extends beyond the bolt.
The car sits level in the back.
What gives?

[William C.]

Re: Rear Suspension

Something is bent, need to find out what it is, frame, trailing arm, Spring? Normal is enough to seat the cotter pin easily in place in the slotted nut. (you do have the cotter pin installed?) if using factory bolts.

[Bradley D.]

Re: Rear Suspension

It is a new spring (although could still be bent I guess). This appears to be a no-hit car so I can't imagine the frame is bent, trailing arm, I guess I need to check. It drives straight and true, and is level on all corners. And now I do not have slotted nut.

[Bob H.]

Re: Rear Suspension

As Bill said, there should be and I say MUST BE cotter pins inserted through holes in the bolts. A castle style nut should also be used. Perhaps someone used regular bolts and nuts. That is a scary thought as I'm sure they should be a grade 5 bolt. If this is not what you have, start by getting a set from most any supplier and replace what you have, then see how the car sits. I believe there is actually about a half inch difference that is considered in spec

Bob

[Michael W.]

Re: Rear Suspension

Is this correct?
At the end of the leaf spring on the left side, the lenght onf the bolt is at the end, while on the right side the bolt extends beyond the bolt.
The car sits level in the back.
What gives?

It helps if people indicate the year or at least generation of the car in question. If you've got a '63-'82, you're seeing a Bubba inspired modification. Aftermarket spring bolts are threaded over much of their length and the nut uses a nylon insert to lock it in place instead of the factory cotter pin. Owners install these to raise/lower the car or in generally vain attempts to level it side to side.

[Bradley D.]

Re: Rear Suspension

Its a 67 convertible. So if I swap out the spring bolts will I have a 'level' problem? Would this be another can of worms I'd be openning?

[Stephen L.]

Re: Rear Suspension

Brad, a photo of the bolt and castle nut w/cotter key, showing exposed bolt threads. Nothing is torqued as the body isn't on the frame yet.

[Michael W.]

Re: Rear Suspension

Its a 67 convertible. So if I swap out the spring bolts will I have a 'level' problem? Would this be another can of worms I'd be openning?

I saw your post on that other site. I'd leave well enough alone, or adjust both nuts to the same setting to see how it affects the stance of the car. My guess is not much.

[Bradley D.]

Re: Rear Suspension

Thanks to all who responded. I'm going to put it back on the lift and check some more and probably replace the bolts and see what happens. I could adjust the right side to be equal in length to the left and see what it looks like.

[Joe L.]

Re: Rear Suspension

Its a 67 convertible. So if I swap out the spring bolts will I have a 'level' problem? Would this be another can of worms I'd be openning?

Brad-----

Yup, you may be opening a can of worms but I'd say it needs to be done. Personally, I would not use the bolt set-up you have on there now.

First, I would do as Mike suggests and adjust the nuts so that they are at the same position on the bolt on both sides. I would position the nuts so that the bolts have the same effective length as the stock bolt set-up. When you've accomplished this, you'll know exactly how the car will sit when the stock bolts and nuts are installed. How do you figure out what the effective length of the stock bolts are? Simply obtain a stock bolt, install a nut and run it down until it stops on the bolt "collar" and measure the length between under the bolt head and the top of the nut. That's the dimension you want to simulate with the existing bolts to see what it's going to look like with the stock bolts installed.

Caution: many Corvettes will appear lower on one side or the other when the stock bolts are installed. My original owner 1969 was like this from the day I took delivery. I have a very strong suspicion that's the condition that someone was trying to correct with the bolt and nut "adjustment" you have now. However, doing this sort of thing is completely bogus. You will likely be otherwise unable to correct the side-to-side height difference if it exists but it's better to live with that than try to correct it with the sort of set-up you have now.

[John H.]

Re: Rear Suspension

Brad -

Here's what the stock rear spring end link bolt looks like.


RearSpringBolt.JPG

[Bradley D.]

Re: Rear Suspension

I did a better measurement using a square with a level. The left rear is 7/8' lower than the right. I measured according to the AIM. It says height should be 9.16" I am at 10 1/8 and 11". I think I will replace whats there with new replacement parts and go form there.

[Joe L.]

Re: Rear Suspension

I did a better measurement using a square with a level. The left rear is 7/8' lower than the right. I measured according to the AIM. It says height should be 9.16" I am at 10 1/8 and 11". I think I will replace whats there with new replacement parts and go form there.

Brad-----


By the way, always replace all of the rubber cushions on the spring end bolt whenever the bolts are removed.

[Joe L.]

Re: Rear Suspension

Brad -

Here's what the stock rear spring end link bolt looks like.


[ATTACH=CONFIG]45000[/ATTACH]

John-----


Yes, in calculating the effective length or installing the slotted nut on the car, it's actually more accurate to install the nut just so the cotter pin hole is clear rather than run the nut all the way down to the bolt's collar as I previously suggested. I think there's probably about 1/4", or so, difference.

[Michael W.]

Re: Rear Suspension

I did a better measurement using a square with a level. The left rear is 7/8' lower than the right. I measured according to the AIM. It says height should be 9.16" I am at 10 1/8 and 11". I think I will replace whats there with new replacement parts and go form there.

Most of the aftermarket bolts are longer than OEM. Since your car is already higher than stock, the shorter GM bolts will make it even worse. Root cause is probably a spring with an incorrect arch or spring rate.