I just bought the truck 2 months and it has a rebuilt engine and tranny. Earlier this week it wouldnt move and our mechanic replaced the tranny tubes because 1 had popped out. Today the truck was rev-ing high at very low speeds and we where having trouble changing gears. How much is it to rebuild the tranny vs buying new? Our mechanic will look at it tomorrow but my gut is telling me the tranny is shot...any advice is appreciated!