My 2000 Dakota has almost 152,000 miles and the transmission is acting up. I first noticed it while I was driving uphill with it in overdrive, it started acting like it was slipping. So I took it out of overdrive and it didn't fix it. I also notice it doing it while driving, when it shifts into 3rd the RPM's drop and it feels like the brakes are being lightly tapped and it does from about 35mph until about 45mph. I have tried driving it differently and it still does it, at the same speed. Any help would be great, thanks!