I purchased my truck about 6 months ago. The problem with the transmission only happens after traveling above 55mph for either short or extended periods of time. I will get in the truck the next day after traveling on the highway and @ roughly 10mph it will shift real hard into the next gear. I normally give it a few days of shifting hard and then it shifts like butter again. I love my truck, but unfortunatly don't know too much about the mechanics... Do I need a rebuild? Any informaiton / advise is appreciated