I installed my lift kit about a week or so ago and almost immediately after I started to notice a loud thud coming from the rear suspension whenever I hit a bump. After a few days I discovered that the rear left upper shock bolt was very loose. I had all the bolts tightened at the Tire Shop when I had my new tires put on. Problem solved... Or so I thought. The problem was resolved for a few days until earlier today when I started to notice a very slight squeak when I hit a bump. Before I managed to get home this squeak was soon followed by the all familiar thud when I hit a big enough bump. It is now located in the rear left only.
I checked the bolts on the shock and they're as tight as can be. I can only duplicate the sound by sitting in the cargo area and jumping up and down. It won't work if I simply rock the vehicle from side to side. If I jack up the vehicle under the rear left side even just a little, the thud and squeak will not occur. I tried physically moving the shock as well as compressing it. No abnormal play or unusual sounds.
... What the crap!

Any ideas? This is really starting to annoy me!