It's quite common for Dodge vehicles to have that problem, I'd start with checking the transmission fluid level and keep in mind that if the fluid is low it could be that it has a leak so check for any leaks , plus if you've ever had the engine over heat on you be sure to change the transmission fluid and filter on it asap or if the transmission has high mileage on it or is around 75,000.
Hope that helps and best of luck.By the way be sure that you have the exact factory recommended fluid and filter used on it and I'd change the gas filter on it especially if it's not been changed on a regular yrly basis.
Note one major mistake that is made is using the wrong transmission fluid or filter kit so be sure you personally see to the right fluid and parts being used.You should also call the dealership up and see if any engineering program updates are available on that vehicle , it runs about 60 bucks plus taxes to have the transmission comp's programming updated=flashed.
