Alright, so I created a thread not too long ago about this, and I have found some more information on this.

The 2000+ Bonnevilles share the same front springs as the 2000+ Deville'*, as can be seen here:


Which is a good thing, because Eibach makes a set of lowering springs for the 2000+ Deville'*.

Now, the rear suspension. After examining exploded views of the 2000+ Bonne'* and the 2000+ Deville'*, they appear to be identical, BUT the springs are not the same PN. This leaves me to believe that they have two different spring rates, hence the different part number.

Bonne Exploded View


Deville Exploded View



Now, I know a few years ago, GM stopped releasing the spring rate info for who knows what reason. This kinda sucks, but nothing I can do about it. So... the next venture I can do is compare the curb weights of the Bonneville'* against the Deville'*. This can kinda give a general idea as to which had the stiffer spring rate.

Anyone have any other thoughts or input on this. Toasty and I have been discussing back and forth over PM about it, figured there might be other interest or input to be had.

Thanks.

I just noticed that they use the EXACT same scans for each of these, which means that they are the same rear end setup, just different springs.

So, if ANYONE has any info on the spring rates or curb weights, speak up! I think we have a match on lowering springs!!!!

Deville has a heavier butt, so figure that for the higher spring rate. They probably share the rear springs with the Park Ave.

So I had figured.

Next I wonder- Will the rear springs lower the car, or actually RAISE the butt end of the car?

And... what effect will the springs have on the auto leveling system?

good find, I'll be keeping my eye on this. My bonnie is in need of some new springs anyways

I might be stupid but.....
If the spring rate is a little higher (weight difference probably isnt much) The deville lowering spring would just stiffen up the ride abit in the already stiff bonnie. However I would bet the spring weight is very close because the Deville springs would have a little more bounce to them to give the Caddy Cushy ride and the Bonneville springs are a little stiffer than normal to improve handling. So even if the weight is a good bit away without trying these springs many questions will go unanswered. So I guess this means one of us needs to try these. I am willing but I bet someone trys before I because I would need a month or so to get the springs and install.


I think I confused myself

You would need hard data, although the Caddy'* weight would suggest the stronger spring.

As for the effect on an autoleveling system... adjust the height to match your new spring height. In theory, it'* easy.

well, Bill, raising the car if it is too low is easy, but there is no way to lower i the car if it comes out too high; since the 00+ use the sir shocks only to provide the extra lift, and do not affect baseline ride height - the springs SHOULD be providing adequate ride-height until they sag

wow.....interesting info....

ill be watching this thread....the 03 sits too high

Design a lowering bracket for the shock that will compensate. Although..along with lowering comes..fixing the geomentry issues.