Transverse Spring

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Mar 17, 2007 | 12:02 PM

GM_96LT4

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From: Sierra Madre

Transverse Spring

Good Morning Everyone & Happy Patti Day,

I have a question and trust me; it has nothing to do with a "coil-over" setup versus the "leaf-spring" issue.

I am not having any apparent problems with my suspension but I am curious, is there a simple way of knowing if your springs are going bad or it's just time to replace them for preventative maintenance routine.

It's like this, I never thought I had a problem with my shocks until I decided that I owned the car way to long for them still to be good. After I changed them; it was a major difference and was shocked how much better it rode.

Now, if I deem that it is time to replace the springs then we can rehash the controversy

, trust me - I am kidding.

Also, I did a search and found tons of threads but couldn't find one that I was looking for.

Any input would be appreciated and thanks in advance,

Glenn

Mar 17, 2007 | 01:39 PM

VtVette

Melting Slicks

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From: Las Vegas Nevada

Hi Glenn. On my computer at my shop I have a great article about the pro's and con's of the transverse leaf spring. The article is from the book "The Newest Corvette" that was published in '83 and documents the design and creation of the C4. The following is from the article:

"It is also totally corrosion resistant and more durable than a steel spring. Any coil or metal leaf spring will eventually sag. The fiberglass spring won't. Also if you compress a steel spring enough times - on the car or in a lab - it'll break - snap right in two. We can run these fiberglass springs, though, practically forever. We've run some rear springs up to eight million cycles in laboratory tests - full jounce and full rebound. As a comparison the old corvette 9 leaf steel rear spring would break at something like 75,000 full cycles".

I wouldn't worry too much about your spring wearing out anytime soon.

I'll post the rest of the article for you this afternoon. It has some great info about the fiberglass spring.

Mar 17, 2007 | 03:25 PM

VtVette

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From: Las Vegas Nevada

OK here is the article I was talking about. You may need to save it and zoom in a little to read it, I can't resize it here on this computer sorry.

Mar 17, 2007 | 04:38 PM

todd_vette

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From: Pueblo Colorado

Pretty much as he says in there. The composite springs are good untill something cracks or breaks them. They are amazing in that they will be almost identical in responsiveness from the first flex untill the one before failure. The only one i have ever seen crack was when my mom hit a pot hole so hard it cracked it at the outter mount...That impact also bent the snout of the crank-shaft...I had never seen that before then either... Why did it have to be my Vette she was driving???

She was driving me home from eye surgury when she hit it and it was hard enough to make me worry about loosing my eye as well.

Actually it became "My Vette" after that.

Last edited by todd_vette; Mar 17, 2007 at 04:42 PM.

Mar 17, 2007 | 06:47 PM

JoBy

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From: Timra, Sweden

Quote:

Originally Posted by VtVette

OK here is the article I was talking about. You may need to save it and zoom in a little to read it, I can't resize it here on this computer sorry.

I have posted this many times before

Mar 17, 2007 | 07:02 PM

VtVette

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From: Las Vegas Nevada

[QUOTE=JoBy;1559410133]I have posted this many times before

So THATS where I stole it from...

"Then Newest Corvette" is 180 pages of inforamtion like this. It's a fantastic book.

Mar 17, 2007 | 10:39 PM

CentralCoaster

Team Owner

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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed

Quote:

Originally Posted by VtVette

I wouldn't worry too much about your spring wearing out anytime soon.

Most of us don't drive our cars in a lab. Spring steel btw, is one of the highest grades of steel and very corrosion resistant.

There are lots of Corvette owners with weak/sagging fiberglass springs. In the real world, they can crack and splinter, and road debris and chemicals eat away at them. Unlike steel, they also suck at impact damage.

To answer the question, you'll need to take a close look at the entire spring surface. Any failures will begin on the surface since it's stressed the most, and has the most potential for manufacturing defects (voids in the resin). Most of the front spring is concealed and would have to be removed to inspect. Generally, a bad spring will give you uneven ride height, but tends to change very very slowly and go unnoticed.

I wouldn't give the spring a shelf life, as it depends entirely on the environment you drive in.

Last edited by CentralCoaster; Mar 17, 2007 at 10:46 PM.

Mar 18, 2007 | 12:15 AM

VtVette

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From: Las Vegas Nevada

I'm only reporting what GM engineers had to say. Don't shoot the messenger. I'm on my 6th C4, all '84 or '85s never had any sign of spring wear. Your mileage will vary. Personally I'd love to see a failed C4 spring. I'm sure they exist. I've just never seen one personally. I agree they are particularly succeptable to chemical corrosion due to fluid leaks. I wish my Jeeps or Full Size chevy pickups had fiberglass springs. If I had a dime for every sagging or rusted out metal spring I've changed up here in VT. Of course I don't drive the Vette in the winter.

Last edited by VtVette; Mar 18, 2007 at 12:40 AM.