One problem related to transmission stuck in gear has been reported for the 2002 Chevrolet Trailblazer. The most recently reported issues are listed below.
Pulling onto the highway, when transmission popped and began to whine. Reverse gear lost and stuck in 1st gear. Took to dealer where diagnosis was failed (stripped) reaction sun shell. Fortunately vehicle was traveling at low speed. Concerned that failure could have occurred on the highway at greater speed. This vehicle was never used for towing or subjected to any abuse whatsoever. This is a common failure in the 2002 models built during a certain time period. Dealer gave some cost concession on transmission replacement, but unwilling to admit component weakness. Called gm customer assistance line with no additional support.