C4 Ride Height - New Springs

[SatansVette]

Greetings boys and girls; Seeking a little input on a subject I can't seem to find and that is, What would the correct ride height be for a C4 Corvette and in this case a 1985. I have recently installed new front and rear springs since they were over 20 years old and now, with the new springs in, it appears to sit up WAY too high in the front. The bottom of the front air damn to the floor is 5.5"... it just looks too high. Is there a standard height one should use and where should one measure from? I'm not sure on the rear now either. Fortunately they can be adjusted. Any ideas or help would be greatly appreciated.

 

[vader86]

5.5-6 inches is the stock ride height.

 

[Ken]

Don't worry, it'll settle to a "normal" ride height in no time at all.

As for replacing the springs due to age alone, I don't think it's necessary unless visible damage is apparent. The springs were cycled for many more miles than we could ever hope to put on our Corvettes, and age doesn't play as much of a part in determining strength as does steel. Of course, that just my humble opinion.

 

[SatansVette]

Ahhh, ok, then it appears that I've done something right! That does make sense about the settling. Ken, you know.... somehow I knew that replacing the springs wouldn't have mattered and I did read somewhere that typically, springs will last much longer than we think and that replacing them probably wouldn't make any diff.... (that was the key word "probably") just as you said! Guess I should have paid a little more heed to those words.. especially after the front and rear springs cost almost 700.00. But, I was having a suspension problem that I could not narrow down and was tired of looking for a ghost, so, I decided to the suspension... replaced every bushing (EVERY) with neo's, tie rod ends, ball joints and of course springs, along with shocks and a few other things. I have solved my suspension problem and who knows what it was that actaually made the noticable difference but more thhan likely was attributed to the bushings and Bilstien shocks. Thanks guys.

 

[Ken]

The springs will begin to show signs of delamination (it will appear to be splitting through the cross-sectional length of the spring) in most cases of weakening or deterioration. That is the time to immediately start thinking of replacements.

I currently have my entire rear suspension disassembled and realize that I should go through it and replace the remaining original factory rubber with new spring insulators and urethane control rod bushings. I've already upgraded to Guldstrand's heavy duty rear axle "toe rod" kit and adjustable camber rods, may as well finish it, eh?

 

[tyrel]

Don't worry, it'll settle to a "normal" ride height in no time at all.

As for replacing the springs due to age alone, I don't think it's necessary unless visible damage is apparent. The springs were cycled for many more miles than we could ever hope to put on our Corvettes, and age doesn't play as much of a part in determining strength as does steel. Of course, that just my humble opinion.

I respectfully beg to differ. Although the front spring is supposed to last the life of the car, I see many early C4s with sagging front ends, and this can only be attributable to an aging front spring. Curiously enough, you don't see this phenomenon in the rear spring. Here, for example, is an 86 coupe with diminished front wheelwell clearance:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2485512012&category=6168

Of course, one wonders if it might have come from the factory like that in the first place, since it seems that no two C4s have the same right height, and sometimes even different ride heights from side to side on the same car. I always assumed that the factory would have made the cars with equidistant tire-to-wheelwell lengths all the way around the car, but now I'm not so sure.

 

[Skant]

When I replaced my front spring (it was delaminating), the car sat way high in the front... since it was only the front, the difference was very obvious because the car had its nose sticking up. Over a couple of months, it dropped about 0.5 - 1.0 inches. Most of it within the first week or two. It did not appear to drop gradually per say... more like it wouldn't move at all... wouldn't move at all... then one day it would drop a ways... and then nothing... and then it would drop again... etc.

- Skant

 

[WhalePirot]

Front ride height is not very adjustable. The spring spacer can be removed or changed to a poly wedge.
I adjust the rear spring bolts for straightline from wheelcenter to wheelcenter, through the diffy and U's. Body panels differ, so L/R wheel opening spaces are not reliable for this adjustment.

Ken, surely you should install poly to deliver the tightness you opted for with the 'G' rear rods; esp. as you have it lying there apart. Not too pricey, either. Energy is just south of me (San Clemente). Lunch, on me, enroute?

BTW, my (aftermarket) rear spring sagged slightly, then broke. I wonder if the extra heat from the 406, through the 3"ers caused the failure. Changed back to the stock Z-51, which was upstairs in the garage, luckily, but pondering coil-overs. Film at 11.

 

[vader86]

Excess heat can cause delamination, thats why the stock Y-pipe has a heat shield on it. GM lost a few rear springs because of it in testing.

But I've never heard of it actually happening to someone.

 

[Ken]

Ya know, it just dawned on me that I should be able to give a pretty good example of how a change of the spring insulators will affect ride height.

I currently have the entire rear suspension out of the car for a third member rebuild, and I just bought new insulators (that's what the service manual calls 'em ) for the old spring. My spring as I said, is in good condition.

Seems logical that there would initially be a half-inch or so increase due to the stiffer insulator (bushing). I'll keep y'all posted.

 

[WhalePirot]

Excess heat can cause delamination, thats why the stock Y-pipe has a heat shield on it. GM lost a few rear springs because of it in testing.

But I've never heard of it actually happening to someone.

Ya have, now!

Guess I'll have to install some heat shielding when I get it running again. THANKS!!!

 

[Ken]

There's a lot of things one can do to damage the spring: high pressure washers can cause delamination; certain chemicals and cleaners can cause delamination and/or deterioration; heat, as mentioned already, can quickly ruin the spring. Ideal conditions would permit the spring to last a million miles or more.

As Mark, Mike, and probably many others have discovered, the cost of a replacement is expensive - $399.00 + last time I looked, so take care of your springs.

 

[SPANISHVETTS]

There's a lot of things one can do to damage the spring:

ad Do not forget pot holes in Poland. Oh well, I needed an excuse to upgrade. It looks like the Pol Pope could have a word with someone about healing those roads.