If it's an original transmission with 230k miles, it might be about due. I replaced my original transmission at about 225k miles with a reman, and I just replaced the reman again at 578k miles.

I suspect the previous owners of my car were a little "casual" about maintenance, the transmission wasn't quite right when I bought the car with less than 200k miles. I was pretty good about servicing the replacement and it lasted 350k miles before it started acting up. A couple of weeks ago, the shifts were a little off and adjusting the cable didn't change anything. I had my indy take a look and the fluid looked horrible so I ordered another torque converter and transmission. It's much better, hopefully I'm good for another 350k miles.