I bought a 2004 Silverado Crewcab with 40,000 miles on it in the beginning of 2011. The truck now has around 53,000 miles on it. A few times over the past month, I have noticed the transmission slipping. Mostly it is from a stop and I press the accelerator and it feel like the rear wheel is slipping( clearly not at low throttle input on dry pavement) and then it suddenly grabs and the truck moves forward. It doesn't seem to slip for long, just enough for it to not seem right. Can anyone provide some insight on what I can do to get this fixed? My main concern is damage to the transmission that is going to cost big $$$$$. Thanks in adavance.