MY 2005 CHEVY TRAILBLAZER HAS A BAD SPEEDOMETER. IT FAILED WITH 20,000 MILES ON IT. IT WILL READ 120 MILE AN HOUR SITTING STILL, THEN IT WILL READ 30 MILE AN HOUR, WHILE I AM GOING 60. IT IS TROUBLING AS TICKETS ARE EXPENSIVE IF I RECEIVE ONE. ON THE INTERSTATE, YOU HAVE NO IDEA HOW FAST YOU ARE GOING. HAS NEVER BEEN IN AN ACCIDENT. GM SAYS $800.00 PLUS TO FIX IT. ONLY HAS 39000 MILES ON IT NOW. THOUSANDS OF THESE HAVE THE SAME PROBLEM. COMPLETELY UNSAFE. THE WHOLE ASSEMBLY HAS TO BE REPLACED TO REPAIR TO FIX IT. *TR