C4 Fiberglass spring breakage?

[Dave P.]

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[Joe L.]

Re: C4 Fiberglass spring breakage?

Has anyone heard of spring breakage becoming an issue when a C4 starts to be driven after a loooooong period if inactivity? My 85 has been driven less than 500 miles since 1994, but is now going to get about 10,000 over the next 18 months.

I have a spot of 'de-lamination' (it's breaking) on the front spring. It hasn't gotten worse since discovery about 2 years ago, but I'm concerned. I have identified a source of used C4 parts locally, but this inventory is the same age as the one on my car. Plus it's been stored in the sun; bad for composites. This part is NLA from GM, and it would probably shatter if installed after being stored in non-compressed position for 25 years, so I don't trust any "NOS" either.

I'm not as concerned with loss of points for a non-correct spring code, as I am with dealing with a broken spring on a cross-country trip. Any ideas?

Thanks,
Dave

Dave-----


I'd be concerned, too, about problems cropping up a long way from home. This possibility is something I'm always "paranoid" about.

You are correct that the GM springs for your application are discontinued. However, Vette Brakes and Products offers replacement springs in several different ratings for your application. Brand new and factory-fresh. I think they're about $400-450.

[Tom H.]

Re: C4 Fiberglass spring breakage?

Dave:

We've seen several broken examples in our shop. I would not say it is common though. I would say you have the warning signs. I'd change it before using it for a serious road trip.

[Franz E.]

Re: C4 Fiberglass spring breakage?

[Franz E.]

Re: C4 Fiberglass spring breakage?

[Mark T.]

Re: C4 Fiberglass spring breakage?

Dave , Jack Brown and myself judged a c-4 at the loews regional two years ago that had a delaminated / broken rear spring. The car was sagging so bad it was very difficult to get under the rear to judge the chassis. The owner had driven the car there and said he had bottomed out in a pot hole. The spring was coming apart in layers. This car was also a very low mileage car.
Good luck with your car, you did fail to mention in your post that it was a crossflag award winner a very nice original car.

[Clem Z.]

Re: C4 Fiberglass spring breakage?

never use any strong cleaners on the fiberglass springs as this will cause a delamination problem. they have found that white wall cleaner will cause this problem. i was told this years ago by a GM engineer.

[Bill M.]

Re: C4 Fiberglass spring breakage?

Ford tried composite leaf springs on the rear of the Ranger. Stone impingement damaged the springs.

[Tom L.]

Re: C4 Fiberglass spring breakage?

Many years ago we substituted Fiberglass leafs in a racing application, they saved lots of weight and worked great. But, we soon found that nicks and chips led to broken springs, we broke a bunch. Don't know how easily that can happen on a C-4 though, aren't they mostly hidden?.