I have a 2001 Durango with a 5.9L V8 Magnum I just purchased. In the last couple of days I have noticed really wierd driving habits with the transmission. Sometimes when you start it and shift into drive it feels as if you are pulling a trailer (takes a while to get going)... then at other times it is just fine. I have tried gears 1 and 2 to see if they do the same thing and they do not. I just did a transmission gasket and filter and the pan was clean and the magnet showed no signs of metal, but yet I have the same issue... and like I said it is intermittent. I guess I am at a loss for words because it doesn't do it all the time... just intermittently. Does this sound like the TCM is going bad??? I have no check engine lights.

 

there is no TCM in your truck as the 5.9 came with the 46re transmission which is hydraulic (mostly), sounds to me like you need to either adjust the bands, adjust the TV cable, and make sure you have enough fluid in there. Also, did you use ATF +4 ONLY??? if not you need to change it again because the wrong fluid in these transmissions will cause problems

 

Also it could be a TPS (Throttle Position Sensor) issue.