Wrong FX3 Shocks?
 

I ordered some replacement FX3 shocks from here:
http://www.eshocks.com/bil_Ind.asp?VC=7Q34&SubChar=Q
and went to replace them today.

When I took the old shocks off, I noticed that the new ones aren't identical. Whereas the old upper shock was dished to accept the rounded rubber insulator, the new upper shock is flat.

I considered just reusing the old upper shock, but the rod on the new shock that has the gear for the actuator is about 1/4 inch shorter than the old one. I've checked and confirmed that they sent me the right shocks for the 89-91 C4.

Here's a picture for comparison.

https://cimg4.ibsrv.net/gimg/www.cor...55c3cf4422.jpg

I'm at a loss as to what I should do. Any advice would be much appreciated.

I just swapped out FX3s on my 94 with a new set that look just like yours and had no problems what so ever. Be sure you limber up the adjusting shafts by turning the little gears at the end of the threaded shafts back and forth by hand a few dozen times. If they are to stiff the actuators will not cycle them properly at start up and the FX3 ride control system will throw a code.

Unfortunately, the FX3 system has two variations - 89-91, and 92-96. Yours are different than mine, although in what capacity and to what extent I have no idea.

From what my research has found, I need to get new lower insulators/bushings/grommets (different sources call them different things) such as these: http://www.ecklerscorvette.com/corve...1989-1995.html

However, I didn't know you had to turn the shafts by hand to limber them up ahead of time. Thanks for saving me having to learn that one the hard way.

One difference between the two shocks is amount of rotation of the shaft. There is a "stop" molded into the gear at the top of the shaft.

https://cimg7.ibsrv.net/gimg/www.cor...e0f1c9dd67.jpg

This pic is from the Captain Z cnc website. He rebuilds actuators for the FX3 and Ferrari systems.

Thanks, I didn't know that!
I just checked and mine have the shorter stop on them.

Bilstein said you can reuse the old bushings, even though they don't quite match the upper shock, and that the difference in height is not a problem. That being said, I'll probably replace the bushings anyway just as preventative maintenance.

I just ordered the front bushings from Eckler's. The rear ones are only available at two places, and I'm not sure they are even the right bushings.

Eckler's I thought only had the uppers. Do they actually have both?

I'm not sure, but I believe my new shocks came with the lower bushings. You can see the bushing in the picture from my first post on the bottom end of the shock.