Coil spring Help

[keith6469]

Ijust finished installing new poly bushings in the rear of the car, now on the front. Question, I removed the old coil springs, and the new AC Delco springs are shorter and the spring ends are not cut the same as the old ones. So just to make sure they didnt miss box that set, I got another set. Low and behold the other set is the same. Whats the answer. Please help.

 

[JohnZ]

The correct GM coil springs were discontinued from service several years ago, and nobody makes reproductions or replacements configured anywhere near the same as the originals; that makes springs a crap-shoot, and you won't know what ride height or harshness you'll have until they're installed and you drive on them. If their free height is shorter than your old ones, they're the much higher-rate (stiffer) springs.

 

[keith6469]

So what your saying John, is that I'll just have to give them a try. Would you suggest installing insulators between the spring and the lower control arm.

 

[Zixxer]

I just went through this on my 1982. My front was so low I couldn't drive the car so I ordered stock replacement TRW springs. When I got them they were shorter then the worn springs I took out. I was worried but then I found the insert that discussed the technology behind newer springs and the shorter spring would work just fine. It did in fact work just fine and restored my ride heights to specs. It feels much better to drive and tracks straighter then before.

I did purchase a set of 1" spacers for the base just incase I needed them. I still have them sealed in the package so if you determine you need a set just let me know. I don't suspect you will after you install your springs.

I will say it was a little bit of a chore getting the spring end to align within .5" of the drain hole on the bottom. The spring would pop out of place in the top but eventually with rotating the spring and enough pressure with the floor rack it held in just the right place.

 

[kiwi vet]

So what your saying John, is that I'll just have to give them a try. Would you suggest installing insulators between the spring and the lower control arm.

Hey keith6469

Take the new springs you have (assuming not on the car yet) and get them tested for compressive resistance. Not sure if thats the right term, but the point is you can measure the weight of the new springs, compare them to the original springs weights from historical record (assumes the old ones are shagged), and derive an answer as to whether they are stiffer or looser than original.

It is important to get this right, as the rule of thumb dictates that the tightest (stiffer) end of a vehicle breaks away first, therefore if the new coils are much stiffer than the originals, leaving the rear spring the same, would dictate that the car would be more likely to push (understeer) than standard.

As stated elsewhere here, given the same pitch & coil size, shorter springs tend to be stiffer.

Hope this helps, good luck

 

[JohnZ]

I will say it was a little bit of a chore getting the spring end to align within .5" of the drain hole on the bottom. The spring would pop out of place in the top but eventually with rotating the spring and enough pressure with the floor rack it held in just the right place.

The only end of the spring that should be oriented is the top, within 3/8" of the stop in the upper frame pocket; doesn't matter where the end is at the bottom - the hole in the lower control arm pocket is only for water drainage.

 

[Zixxer]

Great, I have to look now where the top is aligned...I was looking at the service manual assuming the image was the lower stop. :W

 

[keith6469]

Thanks guys, you have answered questions that no one else could. Im finding out that these cars are a breed of there own, and not everyone can work on them. So i've been doing all the work on it my self. A real learning experience, and a good one at that. Thankyou all for the help.