Whle I don't know the exact details yet. A former coworker (I switched dept's) has a G56 problem. The truck is an 05' dually 4x4 stock. He was decelerating from the freeway to stop at a light. He downshifted to 3rd. The truck immediately grinded to a halt. He said the sounds coming from the transmission were not right. He was able to limp out of traffic in 1st. It turns out 1st gear is the only working gear. He traveled the remaining 1mile to work in 1st gear. Called the Dodge dealer and had them come tow it to the shop. I'm told the transmission would grind in every gear. When I find out what went wrong I'll update here. Being a 12V guy I don't keep up on the day to day issues with the 3rd Gens. Thought some here would be interested on what it takes to destroy a low mileage stock G56.