Transmission fluid level should be checked at least every 10000km. Checking procedure is pretty simple but it is important to follow it as described:
- Drive the Jeep and bring it to a normal working temperature.
- Keep the engine running (idling) for at least one minute before checking the level.
- Make sure the jeep stands straight on the ground level.
- Clean the dipstick area to avoid dirt from falling into the transmission
- While the engine is running and the transmission is in “N” (torque converter fills in both the P (PARK) and N (NEUTRAL))
- Pull the dipstick of the transmission and verify that the oil is in the upper range (between the 2 upper dots). If the fluid is cold, then it should be between the 2 lower dots.
If you have to add fluid, make sure it is ATF +4 (or Mopar fluid). Do not overfill it!
In the picture below you can see the transmission dipstick (circled):