Regen

I took my C4 into a local Chevy dealer to have them put it on the rack and take a look replacing part of the air dam. One of the brackets is broken and the plastic is cracked. That is no big deal.

While up on the rack though we noticed that the front leaf spring is "peeling", that's the best way I can describe it, right in the middle on the bottom side (can't see the top just by looking). It isn't cracked through or anything but a thin layer of the composite is missing right in the middle for about 4 inches across and on either end I could get under it with my finger if I wanted and pull down more of that bottom thin layer of the composite.

The tech that was looking at it said "I have never seen that before". The spring will obviously need to be replaced but, how serious is that? Does the spring need to be replaced immediately?

vette196

REPLACE IT....if it snaps when you are driving it will be ugly. Is it like the attached picture? I bought a set from a forum member. Pull the codes off of the springs, do you have a performance suspension?( Z07 or Z51)

Regen

Thanks for your response.

Not quiet that bad, but kind of yes. I just found out that there is a corvette restoration shop not too far from me. I gave them a call and am waiting on a call back now.

No, it is a completely stock plain old 87 C4.

FASTAZU

Yes time to replace it as it is the start of delamination and will only get worse. Be sure check the other spring also.

Regen

I heard back from the shop. Going to have them replace the spring and check the rear one as well.

Regen

I took it into a local Corvette restoration shop to have the spring replaced but they called me today and said that they cannot find a new spring for it. They have a source on used ones but not new.

I asked them to give me a day or so to see what I can find but sure enough, I can't find one either. I can find the rear spring everywhere but no-one that I can find in a search has the front.

I ended up talking to a company called hyperco that specializes in suspension and does work with composite springs. The gentleman told me that there was only one mold for the OEM front spring and it was destroyed. To make another mold is cost prohibitive.

The last lead I got is to company called Van Steel out of FL. They are closed now and I will give them a call in the morning but their site also shows discontinued.

Does anyone else have any leads on a new front spring?

KurtK

You may want to check out coil-overs

ZHammer

???....I need more details on this mod....please

MatthewMiller

What is the three-letter code on your spring? You can surely find a good used one to replace it. Fauxari08 is one forum member that has an assortment of C4 springs and swaybars for sale. Van Steel has traditionally sold Hyperco leafs, but it looks like they may be out of the fronts and won't be restocking (all the prices say $0 for fronts). Word had it that they had purchased the molds from VB&P (which is out of business), which would be awesome. So far, though, they haven't advertised new aftermarket springs for sale. I hope they do eventually!

Coilovers can certainly be done, but they aren't cheap and they are not at all a simple bolt-in for the fronts of early C4s. For the rears, I haven't seen a kit yet that doesn't make me uncomfortable about the integrity of the knuckle's "ear" where it mounts.

Regen

Update on this, I just got off the phone with Van Steel. There were two companies that were making them. One of them broke their mold somewhere around 2 years ago. The second went out of business. No new front springs are available. It sounds like Van Steel is doing some work to maybe start making them in the future but understandably, it will be a while.

Van Steel put me in contact with a company called C&S Corvette out of FL who has an inventory of good condition springs. My restore shop is going to get me the code off the spring. I am going to buy a used one from C&S and have it shipped over.

Also, I might know what happened to my spring.

C&S said that they don't wear out but acidic wheel and engine cleaner can destroy them.

When I bought the car from a local dealer (not a corvette dealer), the engine was looking bright and shiny and new. The spring is failing at the top of the arch, right under the engine. So it's very possible that someone along the way used an acidic engine cleaner, which then dripped down onto the front spring and damaged it.

81c3

It is true that certain detergents and solvents will destroy the transverse spring. Some say even Simple Green is too harsh... More than likely though its due to age and time. 32 years for any moving car parts is a long time. That spring flexes constantly... they can wear out like everything else. Nothing wrong with a good used unit either.

MatthewMiller

Comments in brackets are mine. Thanks for the updates. I really hope they do start making them, especially the stiffer aftermarket springs like mine. If mine broke today, I'd be stuck having to go the coilover route, and that's a not a good position to be in.

Regen

Is an HKX front spring interchangable with an HMP front spring?

I searched google and some other threads seem to list both for the 87 coupe and as the same weight.

MatthewMiller

It appears to be, yeah. That said, the data I copied says they are 39.9 N/mm, and that's wrong. Those are rates for the rear of that car (FE1 or Z52 cars), and the fronts are probably really 51.8 N/mm. If that's true, then realistically you could also use HMN or FJY, which are both 54.4 N/mm.

Regen

I have a source on a good HMN and I was going to buy it today but the following post confused me.

https://www.corvetteforum.com/forums...spring-id.html

"FRONT 84-87
BMB 102
HMZ 63.5
HKX 39.9
HMP 39.9
HM2? 57.2
HMN 54.4"

So the HMN is much different, but HMP and HMZ appear the same? I do know that the HMN is off the convertable, not sure why it is so much higher though.

MatthewMiller

I've got the same chart as you just posted. But I'm saying the rate they quote for the HMN and HMZ is wrong. That is the rate for the rear of the same cars, and I believe it was just entered in error. The correct rates for HMN and HMZ are probably 51.8, going off the Hib Halverson chart for spring rates. That makes a lot more sense, and the convertible would be just a bit higher because it weighs a little more.

Regen

I see, I am seeing that chart as well, amazing how difficult this information is to accurately pin down. OK I will share this information with the vendor tomorrow, thanks.

dolbnyc

Since the front spring is no longer made. What coil over option is there that's not $2500 bucks. My Audi A4 was only like 1K.

eutu1984

I thought I would ad this,I was talking to a rep from Van Steel at Corvettes at Carlisle and he said that in the next six months that they would start making front springs for the C4's.

Regen

Update on this. My restore shop has a source that was at Carlisle and found the correct HMP spring in good condition. So it looks like I will be back on the road soon!