I was travelling down the highway at 100 kph (60 mph) on dry pavement and just crossed a bridge and began up the other side of the incline and the transmission shifted down into first gear locking the rear-end up and throwing me off the highway in a 360 and landing back on the road. When this happened the new engine was red-lined until I could shut it off. The transmission would not shift out of 3 of 6 gears for the rest of the journey. The outcome would of been very different if it had occurred 100 meters earlier on the bridge.

The dealership after some negotiating plans to replace the transmission verses fix it with a new one, but that is far as the sales manager told me they would take it. The transmission was 'cooked' and had lots of metal in it. This incident most likely has damaged the entire drive train and I feel GM will do nothing and hope it doesn't break down again causing me lost time and wages.

Update from Feb 11, 2015: Transmission was replaced by Dealership (SHAW GMC)

Now numerous other issues developing...