Questions about my new front monoleaf spring...

[Skant]

I just got my vette back from the shop today. $950 for a new front spring. The old spring was delaminating and coming apart.

Now my vette's nose is sticking up in the air... the front of the car is up higher than the rear end! The shop tells me that it's normal, and that it will settle in a week or two. I sure hope it's true, because I feel like I'm driving a 4x4 again right now...

I thought my vette was lowered. Its front was definately lower than a normal vette. But now the shop thinks that maybe it was actually sagging because of the damaged spring, not because it was lowered. So I might be disappointed because I did like having it that low.

Where previously there was about 2.75 inches between the bottom of the front spoiler and the ground, now there's about 6.25 inches. Is it really going to 'settle' 3.5 inches lower than it is right now?

I'm hoping that it will come back down to the same height it was before, but I suspect I'm going to be disappointed.


The other thing I got to thinking about was the relative stiffness between the front and rear springs. If the front is new, and the rear is seven years old, would that affect the balance of the car?

I'm not sure how much these springs lose stiffness with age (if they really do at all). But if they lose much stiffness after seven years, then I expect I'd have a car which is more prone to understeer with a front spring that's stiffer because it's newer than the rear spring.

I'm hoping that these springs don't lose much stiffness with age so that it will still balance the way it was meant to. Otherwise I'd guess I would need to replace the rear spring as well... ick. I don't want to spend _another_ grand.

Of course, if the springs did weaken noticably with age, vettes would tend to run lower and lower and lower to the ground with each passing year. Yet their ride height doesn't change much over time, I think. So maybe significant stiffness loss in springs is something that only happens when they are very old or damaged.

- Skant

 

[Jack]

Where previously there was about 2.75 inches between the bottom of the front spoiler and the ground, now there's about 6.25 inches. Is it really going to 'settle' 3.5 inches lower than it is right now?

I'll tell you right up front ... I have absolutely no direct experience w/ any sort of composite springs. Right or wrong ... common sense tells me it ain't gonna settle 3 inches in a week or two. That dog won't hunt! Maybe your previous setup had been lowered ... I recall reading here that to lower a C4 front is not complicated. Or maybe your old spring had a lighter load rating than present. Or maybe my common sense needs adjustment. Hopefully those with direct experience will chime in.
JACK:gap

 

[Ken]

I don't know what to tell you about your current ride height, but as for the monoleaf springs...

The springs were designed for light weight -- 8 pounds versus 41 pounds for the steel spring it replaced. Also, because it doesn’t rust, a composite spring is about five times more durable than a comparable steel spring.

_ken

 

[SPANISHVETTS]

When I replaced the rear spring one side settled about ½ an inch in the first few days. Since it was readjusted there has been no farther change. The new spring is now 5 months and 2500Miles old.

GM specs list your car at 4.2 inches minimum ground clearance.

 

[BigRed]

I was to understand 4.5 inchs off the ground is the factory specs.

Now as for your "Lowerd car". Your mechanic is very much correct.

Think about it. take a piece a 7 ply wood now put 100lbs on it now take away plys one at a time. What happens? The wood will arc and arc and arc lower and lower till it breaks.

As for the spring breaking in? No idea but do as your mechanic says. If the time expires and your still a good 2 inchs high take it back.

If your want even running height change out your rear spring as well. This way both are new and strong and even.

 

[Skant]

Well, after the first day I've measured it again, and it hasn't lowered at all. I would expect that if it's going to 'settle', it would move the most early on, and then slow down.

The shop seemed pretty certain that it will lose height over the next couple of weeks. They say it's normal. But they didn't have an estimate of how much it would lose.

I asked them about the remedies if it didn't come down, and they didn't really seem to want to talk about that. I suspect that if it doesn't come down, I'm going to have a fight on my hands to get them to take care of it.

I mean.. the front of the car is higher than the back now. On my way home from work today I noticed that my low beam headlights were now high beams...

They tell me that the way these cars are lowered is to extract the front spring (again) and replace the mounts with ones that are slightly shorter. It didn't look to me like this method would get more than a half an inch. I thought lowering was done with a shorter bolt through some part of the suspension. They said it's just done that way on the back of the car... the front is different and much harder.

I'm wondering... if it _is_ running high because they did something wrong in putting it together... what could that something even be? It's sitting nearly 2 inches taller than it's supposed to for a stock vette. And nearly 4 inches taller than it was.

Btw, I'm measuring the distance between the bottom of the front air dam and the ground. I think this is supposed to be the lowest point on the vette, right? (Though at the moment I actually have more ground clearance in front than in back...)

I don't know how to resolve this problem except to just wait and see if it does actually 'settle down'. But at the moment I have little faith that it will.

- Skant

 

[Eagle85C4]

Two things....1) After raising the car and allowing the shocks to fully extend causes them to remain extended for a certain period of time till they settle back to it's average ride position. Basically all the fluid has been allowed to pass to the bottom of the shock, whereas usually there is fluid on both sides upper and lower. Driving and taking a few bumps or corners allows the shocks to settle back.
2) The fiberglass is new and never had weight on it. It will also loose some of it's initial flex after you drive it, kinda like a new pair of jeans...or sneakers.....new kinda stiff, but after you wear them for a bit and they get broke it the fit is just fine...

 

[Skant]

I'm feeling a little relieved to hear some confirmation that the car may actually come down.

Does it really take multiple days for this stuff to get straightened out? Considering that it doesn't seem to have moved so far in the first day?

- Skant

 

[Eagle85C4]

Find a parking lot somewhere, where you can do some hard corners...make it dip. take a measurement before and after a few turns in either direction. I am sure you will see it come down. It will just take a bit of time for it to settle in....just be patient...

 

[Skant]

After two days, it still hasn't moved. It's still sitting at 6 1/4 inches up front. I've been wobbling it back and forth on the freeway, making hard turns, and stuff like that to make the suspension move. Maybe I haven't done it enough.

It does feel to me like the suspension is softening up though, even though it's not coming down. I'm not sure if that's just psychosomatic, or maybe I'm just getting used to it.

I'd feel better if it was at least moving down a wee little bit... at least some indication that it was going to come down. But it hasn't moved down even a small fraction of an inch yet.

You know... I kind of wonder if maybe it's more or less at it's maximum height travel right now. The car does feel kindof bouncy. Maybe the spring is loosening up, but it won't actually start lowering the car until it loosens past some threshold... because it's currently held against the top of the travel.

Maybe it's progressive tension with high resistance near the ends of the suspension travel up or down. And it's just pushing against the up right now.

How much travel does this suspension even have? At the moment, it's staying at almost exactly 2 inches above stock height. Does the suspension travel even go much farther than that?

- Skant

 

[compyelc4]

skant,

I feel your pain. Keep your cool. That height is not going to settle in 1-2 days. It may take weeks. You've only got about 3/4" to go. I just took a peek at my '95 (20K miles). The height of my front spoiler is 5-1/2" (about center). I'm running totally stock. You are only 3/4" higher! That does not seem to be too much for a new leaf.

How do you know that your rear end is not sagging? If it is that would naturally tend to shift weight to the rear thereby raising the front end a bit, would it not?

Go measure the distance to the bottom edge of each rear wheel opening. Let me know what that is. While you are at it take the same measurement on each front wheel opening too. We can compare them.

What size tires are you running front and rear?

Ted

 

[Skant]

Well, today it actually started dropping. It has dropped half an inch. Each time I drive it now I can measure it dropping a bit more. So that's a big sigh of relief. At least now I have real evidence that it's not just going to stay with its nose pointing upward.

Still don't know exactly how far it will ultimately come down. But at this point, the car is nearly level, and that's actually the most important. It _feels_ really weird with the car tilted backward at all.

Guess you folks are right about just being patient. I fret about my vette entirely too much. It's my precious baby, you know...

compyelc4: 5 1/2 inches under the spoiler? That's 1 1/4 inches higher than what GM lists as the minimum clearance. Again, that's assuming that the spoiler is the lowest point on the car. I wonder if yours is really the typical height? Might it be bent upward somewhat? I know mine is bent upward a bit, but I'm measuring where it would be if it wasn't bent. I wonder if there's much variance in ride height car to car?

I'm not sure what you mean exactly by 'the bottom edge of each wheel opening'.

And it is running the stock FE1 sized tires.

- Skant

 

[wx briefer]

Degreasers will Kill the fiberglass spring!!! There is a special coating on our springs that can be removed be strong degreasing cleansers. Result - delamination!!!

Eagle One wheel cleaner will also destroy the protective coating on the spring.

This tip was passed on to me by a retired vette engineer.

I use only mild zaino wash on everything. So far, so good.

 

[warren s]

Skant

I replaced my front spring with the standard one from Vette Brake Products. It was simple job, there was only one way to put it in and back togeather.

It took more than a few weekends of long trips before it settled. Soft highway rides wont do much, but i really didnt want to drive over the bumps in my area so I had to wait. The car looked wrong for a while but it did settle down.

ANOTHER LESSON TO LEARN - low miles does not mean less problems. My 95 had 12k miles on it January of 01. The spring looked fine when I inspected it before buying the car, but soon after it also started to delaminate.

 

[Skant]

How quickly will degreaser kill the spring, I wonder?

What if the spring was fine before my car was sold. But the GM dealership obviously thoroughly cleaned the car and the engine compartment. Perhaps they sprayed it underneath with degreaser. The delamination was occuring on the bottom of my spring, and the shop couldn't come up with a reason why it was happening since there were no signs of taking a hit or being messed with.

This failure occured less than three months after buying the car. It was a GM certified 'pre owned' car. Which implies that the damaged spring wasn't damaged when they inspected it (it was _very_ visibly obvious... fragments of the spring were sticking downward. Even the most basic inspection underneath the car would have noticed it).

I wonder if the same thing happened to warren s and I? If both cars had to have their front springs replaced almost immediately after purchase because of the way they were cleaned for sale.

A very interesting notion. How would a buyer even be able to avoid such a situation, were this really the case?

And wheel cleaners can also delaminate the spring? Which ones, I wonder? I'm using Meguiar's all wheel cleaner... the one that's safe for my painted/clear coated wheels. Perhaps the stronger wheel cleaners (the ones that can eat paint) might be dangerous for the spring if they overspray enough?

warren s: Nice to hear from someone else who has actually had this done. That plus the fact that it has actually started to lower down makes me feel confident in the repair now.

More than a few weekend trips, mm? It sounds like yours is a weekend warrior type. Mine is my daily driver. And I have to commute from San Jose to Fremont and back every day. And I am actively working the car to try to bring it down. So it sounds like my final results will come much faster.

Did you happen to measure it, btw? Ie. how many inches had it dropped when it had finished settling?

Now the only question seems to be what its eventual height will land at when its done settling.

- Skant

 

[warren s]

Skant

i never measured the ride hight, but i did notice the front was to low afler a few drives over the speed bumps in my area. the front was lower than the rear to begin with. the origional spring had quite a thin coating on it, sort of like black paint. from what I was told the spring can start to "peal" for many reasons, like a crack forms in the resin. from seeing the spring out of the car and hanldling it, I really doubt wheel cleaner would do it.

the flexing of the spring alone causes failue, its in a place thats very hard for a stone to kick up and hit. lots of these are sold, and by many vendors, so I think this is a common issue.

after a few months the new spring settled down to the same ride hight as the rear, the car looked level.

give it some mileage.

 

[Black94]

Skant... don't worry, the front will drop, but it could take weeks or even months as others have stated. There is no adjustment except for changing the height of the rubber "wedges" above the center of the spring. In the mean time...

There's a good possibility that the entire car sagged somewhat over the years (giving you that nice low look). I can't say what your rear spring looks like, but it's very easy to adjust, thereby giving you a "level" ride regardless of the front height (at least your front nose won't be pointed up). Without spending a penny, and taking only about 10 minutes, you can raise the rear height by screwing in the castle bolts on each side of the rear spring. Just look under the car next to each rear wheel. There is a long (9") bolt going vertically through the spring. Pull out the cotter pin, and screw in the bolt (to raise), or screw out (to lower) the rear end. You don't even have to put the car up on jacks... easy... :Twist

Now, chances are that the rear spring rubber cushions (at top and bottom of those long bolts) are shot... really compressed, and hard as rock. That would tend to lower the rear also. If you wish, you can easily replace them. Put the rear of the car up on jacks. The wheels will drop under their own weight. Remove the wheels, and you will see the long bolts... now completely hanging loose and really easy to remove. Replacement cushions are $15.95 from VBP (www.vbandp.com). This will take care of the sag. If you wish, order the cushions with two 10" bolts for better adjustment (and lowering cabability). I'm planning to do that myself this week, and considering lowering the front as well...

To lower the front requires replacing the wedges on top of the front spring. I've read that the spring will have to be completely removed, but it looks to me that with the wheels off, I could remove the spring's center bolts, then use a sharp chisel, or exacto knife, or the like to cut away the old wedge... not too difficult, I don't believe. Has anyone out there ever done this???

 

[Black94]

OK, guys... here ya go...

Even though no one posted here lately, I did look up the ride height spec in my '94 Corvette Shop Manual (p. 10-3-2), and thought I'd put it here in case anyone could use it later. I don't know if it's the same for all C4s...

With your Vette on a smooth flat surface:

Front- measure from ground up to bolt under front wheel well panel. That's the vertical bolt just behind the wheel opening, under the frame on each side... 185mm (7.28").

Rear- measure from ground up to lower bolt of trailing arm bracket. That's the horizontal bolt holding the lower trailing arm in the bracket just forward of the rear wheel on each side... 323mm (12.72").

There were some other chassis specs mentioned, but I couldn't find anything about the front spoiler height. If I do find it, I'll post it.

Good luck!

 

[Skant]

Well, so far the front end has dropped from the 6 1/4" at the start to about 5 5/8". So it's dropped about 5/8".

My spoiler is folded back a bit... if I pull it forward, it measures 5 1/2" from the bottom. Which is the same as compyelc4's measurement. I'm assuming his car is coup, not a convertible (which I hear sit higher to accomidate the X brace)?

That makes the car approximately level. Still maybe fractionally higher in the front than in the back.

So it sounds like I may be at the stock height now. It's just so much higher than it was, it seems a little odd to me.

So I guess that would mean that the shop did the job right. Unless maybe it's at the right height for a convertible and not a coup or something. I wonder how the different height for those two is even accomplished? Are there two different springs maybe? (might I have a convertible spring?!) Or does the convertible have some different offsets in the suspension somewhere?

Someone somewhere mentioned that springs could be identified by a letter code stamped on the bottom somewhere? Where would I find that and how might I know it's the right code?

Black94: I'm gonna measure from your points in a little bit. Thanks.

- Skant

 

[compyelc4]

Skant-

I, indeed, have the coupe. Glad to hear you are almost happy with the situation.

Ted