I thought I would share a finding I made this week about a clunk I was hearing in the back end. It was a little hard to tell if that's where it was coming from since I also had issues with the front stabilizer bar bushings and links but I figured that since I also had to replace the shocks and the fuel filler pipe assembly, I would take a look at the spring bushings.
I would up replacing both pairs of bushings for the rear of the springs. I found that in particular, the passenger side was worn completely away and there was metal to metal contact between the eye of the spring and the roll pin that goes through the bushings. The bushings in the top of the shackle were like brand new which was surprising considering how bad the lowers were. Since the van has 158,000 miles on it, I suppose that this was something that wasn't unexpected.
So, if you hear a clunk coming from the back, these bushings are a definite possibility.

 

Thank you for giving a heads up.