Just noticed this last night, 1995 Tahoe, 69k miles. The first "clunk" sound happened when I had to stop very quickly to avoid a deer in the road. I did not notice it again until today. It only happens when going over rough pavement, bumps, etc. It is only on the front passenger's side. Where should I start? Would the most common thing be a blown shock? It also almost sounds like a spring shifting slightly, kind of hard to describe. The truck is on the original suspension components.