I took my first trip towing my trailer last weekend with my new 04 2500hd and going up a big mountain road the transmission kept down shifting and i would be running right at redline for like a minute at a time sometimes. I was in tow mode of course. The engine and tranny temps stayed fine but it was pretty scary. And then coming home when it would down shift when i put on the brakes it was at redline too. By red line I mean about 3000rpm which is actualy just before redline. I am asuming this is normal. Is it? Going up the hill I didn't even have it floored. If it weren't for the tach I wouldn't have known. I didn't feel any excessive vibration or anything. Am I tearing up my engine or what? Also I want to get the factory spare tire lock that is keyed the same as the ignition. Mine didn't come with it and I haven't seen it on any of the accessory sites on the web. Can it be bought after the fact or do you have to get it from the factory?