Recently my transmission began slipping constantly and not shifting as easily as it should. I took it to a shop and they told me the transmission needed replacement. I agreed blindly based only on the fact that this is a 14 year old truck. I get the truck back after the transmission replacement and it runs fine for 2-3 days. Eventually the truck runs exactly the same as before. Mad as i am, i am more interested in finding out what is wrong. I have been told by the mechanics that did the work that it could be the TCM and ECM that is making the transmission shift so poorly. Any input is appreciated!