Two problems related to automatic transmission have been reported for the 2007 Chevrolet Trailblazer. The most recently reported issues are listed below.
Transmission line between radiator and transmission rusted out. My vehicle is a 2007 Chevrolet Trailblazer with 59,000 miles.
While accelerating onto a major roadway, my vehicle completely lost power. As the speed limit was 55mph, I had to cross my finger and pick a spot to maneuver the vehicle off the roadway and hope that it had enough momentum to do so. My vehicle is still in the shop however anecdotal evidence from the internet finds that the 4l60 and 4l70 are rife with failures that result in complete loss of power of the vehicle. The faulty part seems to be the "sun shell" and has faults across the gm lineup. I'm very surprised they have not been forced to recall this defective transmission.