rear/mid section clanking over bumps

OK, I'm cheating a bit since my van is a 93 Silhouette, but they're all the same...right!

I've got a terribly annoying thunking/clanking sound coming from the mid to rear part of the van when going over bumpy roads. I've gone as far as removing the faulty compressor, replacing the air shocks w/ gas shocks, and tightened everything I could find in the vacinity of the rear wheels.

Any ideas?

Check the heat shield over the muffler, or check the exhaust system it's self could be loose or outer shell of muffler has come apart.

rolled under the van today and rocked it up and down.
I noticed two things that could be making the noises I've been hearing.
1. the exhaust mount, not the rear on but the one near the gas tank, would rattle. The rubber piece seemed to be dried out, so I sprayed some wd-40 to replentish it. we'll see how long it lasts
2. the pass side rear shock, where the bolt goes through bottom of the shock, had some play in it. The bold has a smaller diameter than the hole. Anyway, tightened it up a bit.

all for now

the only other thing I can think of is a bad trailing arm bushing, but I'd put my money the shock with the loose bushing being your problem.

the shock was the noisyest when I was under the van

much better now!