Truck has been making a clunking sound for over a year and has gotten worse. Recently took to Jimas Transmission to have transmission evaluated. Have been told that transmission needs to have a rebuild or new transmission $4500-6000. The truck has just over 67000 miles on it. Understand that there are class action suits regarding Gm being aware of the flaw in the transmissions. I have contacted both Chevy dealer and GM via certified letter and GM via email, and received no response regarding a goodwill repair.