Two problems related to hatchback/liftgate have been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
I purchased this vehicle in Feb 2008. I opened the hatch for the first time and when I lifted the hatch, I began to hear a lot of breaking and bolts flying. I got it to close securely and didn't have any problems. Then one day, I was driving my truck and the back hatch began to shake. I continue to drive the vehicle. After driving for another few minutes the hatch began to fall backward. I never reach the ground, it was held on by the lights that connect the top light. I went to a dealer that repaired it supposedly. A few days later it done the same thing. I attempted to get it repair a second time. It wasn't successful either. This time I couldn't get it closed. I was told it was a problem amongst a few Trailblazer by my insurance company. Nothing has been done as of yet. The only solution that I was told that may help the problem is paying $1,100 to buy another. According to a local dealer the window doesn't belong in the vehicle. The whole set up is not the way it should be set up. My vehicle has a bracket holding the window up but there isn't a bracket on any website.
While my vehicle was parked, the rear hatch window self exploded. It was witnessed by many general motors employees. Checking on the web, I found that this is more common than expected. Happens mostly in chevy Trailblazers and Ford escapes.