One problem related to vehicle shudder has been reported for the 2002 Chevrolet Trailblazer. The most recently reported issues are listed below.
I was driving on interstate 80 in 2 wheel drive low at 65mph. The vehicle began to vibrate and I looked at the 4 wheel drive selector switch and the light was flashing for all wheel drive. This should only happen when the switch is turned to that position. Then the rpms on the vehicle red lined and the light went to solid green on 4 wheel drive low. At that point the vehicle went into a 360 degree spin on the interstate. Luckily I did not hit anything or anyone. The vehicle came to rest in a ditch. I was able to drive the vehicle off the interstate and when doing so the selector switch was shifting between all the options from 4 wheel drive to all wheel drive. I stopped the vehicle and let the vehicle run while I waited for a tow truck. While the vehicle was in park the lights started flashing and the vehicle was shifting in park. Each time the vehicle shifted the vehicle would lunge forward 2 to 3 feet. My family was in the vehicle at the time and are afraid to be in this vehicle. The dealership says the computer is showing no malfunction codes. They have driven the vehicle and the problem has not happened to them. This vehicle is unsafe. Dt.