Mine is doing that. I know I have to replace a bushing on a rod that runs under it ( don't know what the rods name is atm). Due to a worn or missing bushing it moves when I hit the slightest bump and it hits against my muffler making that banging sound.

 

late update, but better late than never, right? i turned out to be the guide pins and bushing on 1 or both brake calipers. fairly cheap fix(under 100 including labour)

 

I had a problem similar to this on my 91 gmc jimmy and I found out the torsion bar mount (bushing) was worn all the way through causing the crossmember to tap the metal on the chassis making me think it was suspension related. Don't know if this is your problem or not but could be something to check up on, if you still have them.

 

,ime was upper shock mount

 

The same noise I had, it was the passenger side shock bolt was not tight, it was causing the noise.

That drove me nuts for 2 years!!!