Each trailing arm appears to have one inner and one outer bushing.

My trailing arms look brand new, so, I'm not taking them out.

I've considered that. There are two schools of thought. One is the fact that the springs don't last forever and they need to be replaced after a certain time period. But, if this were true, why is there no sagging of the front end after 18 years?

The other school of thought is that the ride height and the rear wheel camber will be restored with the replacement of the rubber parts. The spring is not the culprit.

So, I thought that I would lay the question to rest by replacing the rubber spring perch seats and reinstalling the old springs. If the ride height is restored, then we have a definitive answer.