Originally Posted by Redrider94
If its a manual make sure you can get the fill plug loose first, ( nothing worse than having your transmission drained and no way to fill with new oil).
That was me! Took some work but finally got it out. Got nerve damage in my thumb from smacking it on the skid plate too.
Being a newbie at Jeep ownership, I went and bought a Haynes manual. Not too bad for some general stuff but a shop manual will be your best bet if you want proper details. I also sought people who were knowledgeable (You're in the right place).
Collect what you will need ahead of time for the type of transmission you have. Mine is an AX-15.
Get the proper oil. There are many opinions here. Synchromesh is a popular one. Get yourself an oil catch pan. I used a large round one because as the oil drains into the container in the center, I can see if there are metal shavings on top, however, any large pan can work. Ensure you can take out the drain and fill plug (AX-15 drain on the passenger side low on the passenger side and fill higher on driver side of transmission case).
Drain the goo in the case then replace the plug. Using a hand pump, pump in the new oil until it runs from the fill port. I've read several times "fill till it spills" or some variation. Make sure you torque the plugs to factory recommendations. Drive it around a bit then check to see that there are no leaks. After I got the fill plug removed it took me about 20 minutes to complete the task, with lots of beer break time while waiting for the case to drain.