I had this in a post but I created a new one anyways.........I believe it is a 4L60E. I did a tranny flush with a B&G machine so far but nothing else. I haven't had a problem with it but when I got it the tranny fluid was pretty bad. Now its fine but just one time it did something weird. I got to stop light and stopped completely on a slight incline. I started out pretty quick and it didn't move. I laid off the gas and hit it again and it went just fine. Only time it ever did it but its got me worried. Some say its a computer problem and needs flashed, other people tell me it needs the filter replaced and others tell me its a sign it about to die! I don't know what to do.