I was driving through town at 35 mph about 7 miles from home when I came to a full stop at a traffic. When the light changed I accelerated and at that moment felt a large clunk. My transmission would not shift out of 1st gear (8 speed transmission & 6.2L V8). I pulled into the parking lot of a nearby convenience store and turned off the motor for 5 minutes. Then I started the truck again and shifted into drive and still the truck would not shift out of 1st gear. Tried to manually shift out of 1st but still no luck. Drove home on back roads then called AAA to have my truck towed to Chevy dealer.

Judging by the reaction of the service person, the 8 speed transmission has more than its share of problems. Avoid the 8 speed transmission.

Dealer is doing their best to determine the cause of the electrical communication loss. Several times it occurred the fault codes indicated loss of communication with transmission control module. So far 6 episodes and the dealer has reproduced the fault on their yard but can't find problem. Not sure of the final outcome yet.

Common occurrence is the truck will not start in late afternoon after sitting in 95 plus degree weather for more than 3-4 hours. First indication is the auto start will not function, next the first turn of the key gets dash lights on but no start. Recycle the key, truck will start followed by check engine and stability light coming on. Truck then will be stuck in low gear until codes are reset or limp mode with no dash function at all.